MANTECH INTERNATIONAL CORP - Annual Report: 2005 (Form 10-K)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10–K

For the fiscal year ended December 31, 2005

OR

For the transition period from                      to                     

Commission File No. 000-49604

(Exact name of registrant as specified in its charter)

12015 Lee Jackson Highway, Fairfax, VA 22033

(Address of principal executive offices)

(703) 218-6000

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act:

Class A Common Stock, Par Value $0.01 Per Share

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨    No  x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act.    Yes  ¨    No  x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of the registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

The aggregate market value of the voting stock held by non-affiliates of the registrant as of June 30, 2005 was $552,757,154 (based on the closing price of $31.04 per share on June 30, 2005, as reported by the Nasdaq National Market).

There were the following numbers of shares outstanding of each of the registrant’s classes of common stock as of February 28, 2006: ManTech International Corp. Class A Common Stock, $.01 par value per share, 18,028,522 shares; ManTech International Corp. Class B Common Stock, $.01 par value per share, 15,065,093 shares.

DOCUMENTS INCORPORATED BY REFERENCE

Certain portions of the definitive Proxy Statement to be filed with the Securities Exchange Commission pursuant to Regulation 14A in connection with the registrant’s 2006 Annual Meeting of Stockholders, to be filed subsequent to the date hereof, are incorporated by reference into Part III (Items 10, 11, 12, 13 and 14) of this Annual Report on Form 10-K. Such definitive Proxy Statement will be filed with the Commission not later than 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

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PART I

Item 1. Business

This Annual Report on Form 10-K contains forward-looking statements that involve substantial risks and uncertainties, many of which are outside of our control. We believe that these statements are within the definition of the Private Securities Litigation Reform Act of 1995. You can often identify these statements by the use of words such as “may,” “will,” “expect,” “intend,” “anticipate,” “believe,” “plan,” “seek,” “estimate,” “continue” and other similar words or variations on such words. Additionally, statements concerning future matters or matters that are not historical are forward-looking statements. You should read our forward-looking statements carefully because they discuss our future expectations, make projections of our future results of operations or financial condition, or state other “forward-looking” information.

Although forward-looking statements in this Annual Report reflect the good faith judgment of management, such statements can only be based on facts and factors currently known by us. Consequently, forward-looking statements are inherently subject to risks and uncertainties and actual results and outcomes may differ materially from the results and outcomes discussed in or anticipated by the forward-looking statements. We believe that it is important to communicate our future expectations to our investors. However, there may be events in the future that we are not able to predict accurately or control. The factors that could cause or contribute to such differences include, but are not limited to, those discussed in Item 1A “Risk Factors” below, as well as those discussed elsewhere in this Annual Report. We urge you not to place undue reliance on these forward-looking statements, which speak only as of the date of this Annual Report. We undertake no obligation to revise or update any forward-looking statements in order to reflect any event or circumstance that may arise after the date of this Annual Report. We also suggest that you carefully review and consider the various disclosures made in this Annual Report that attempt to advise interested parties of the risks and factors that may affect our business, financial condition, results of operations and prospects.

In this document, unless the context indicates otherwise, the terms “Company” and “ManTech,” as well as the words “we,” “our,” “ours” and “us,” refer to both ManTech International Corporation and its consolidated subsidiaries. The term “registrant” refers only to ManTech International Corporation, a Delaware corporation that is the successor by merger to ManTech International Corporation, a New Jersey corporation. As a result of the merger, in January 2002, we reincorporated from New Jersey to Delaware.

Business Overview

ManTech is a leading provider of innovative technologies and solutions for mission-critical national security programs for the Intelligence Community, the Departments of Defense, State, Homeland Security, and Justice, and other U.S. federal government agencies. Our expertise includes engineering, systems integration, software services, enterprise architecture, information assurance and security architecture, intelligence operations and analysis support, network and critical infrastructure protection, information operations and computer forensics, information technology, communications integration and engineering support. With approximately 6,000 highly qualified employees, we operate in the United States and over 40 countries worldwide.

In 2005, we had revenues of $980.3 million, an 18.5% increase over our 2004 revenue of $826.9 million. We have grown substantially in the last four years, from revenues of $431.4 million at the end of 2001, just prior to our initial public offering (IPO) in February 2002, to our current levels today. We derive a substantial majority of our revenues from our customers in the Intelligence Community and the Department of Defense:

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Our Intelligence Community and Department of Defense customers include the Office of the Secretary of Defense, the Department of State, the Department of Homeland Security, various intelligence agencies, joint intelligence task forces, the U.S. Army, Navy, Air Force and Marine Corps and joint military commands. We also provide solutions to federal government civilian agencies, including the Department of Justice, NASA, and EPA, as well as to state and local governments and commercial customers.

Industry Background

The federal government is the largest consumer of information technology services and solutions in the United States. We believe that the federal government’s spending on information technology will continue to increase in the next several years, driven by the expansion of national defense and homeland security programs, the continued need for sophisticated intelligence gathering and information sharing, increased reliance on technology service providers, due to shrinking ranks of government employee technical professionals, and the continuing impact of federal procurement reform and Office of Management and Budget mandates regarding IT spending. Federal government spending on information technology has consistently increased in each year since 1980. Input, an independent federal government market research firm, expects this trend to continue, with federal government spending on information technology forecast to increase from $59.2 billion in federal fiscal year 2005 to $78.8 billion in federal fiscal year 2010, representing an annual growth rate of 5.9%. Moreover, this data may not fully reflect government spending on classified intelligence programs, operational support services to our armed forces and complementary technical services, which include sophisticated systems engineering.

Across the National Security community, we see the following trends that will continue to drive increased spending and dependence on technology support contractors.

Increased Spending on Network Centric Warfare and Support to the Warfighter. The Department of Defense is the largest purchaser of information technology in the federal government. For fiscal year 2006, the President has signed a bill that authorizes $410.8 billion in defense spending. This same appropriations bill includes supplemental funding of $55.8 billion to the Department of Defense, with the President preparing an additional request of $70 billion to provide funding for the Global War on Terror and operations in Iraq and Afghanistan. For fiscal year 2007, the President has requested a budget of $439.3 billion, a 6.9% increase from fiscal year 2006, excluding supplementals generally used to support current ongoing operational efforts and the Global War on Terror.

In addition to the recent budget request, the Department of Defense recently completed its Quadrennial Defense Review (QDR), which is published every four years, and provides the Department of Defense’s plans for future strategic direction, including procurement trends. According to a Department of Defense QDR summary, the QDR is aimed at emphasizing agility, flexibility, speed, responsiveness and pre-emptive military concepts, which all rely on information technology systems. The 2006 QDR also emphasizes the increasing importance of net-centric warfare, which involves enabling critical relationships between organizations and people to accelerate the speed of business processes, operational decision-making and subsequent actions. According to the QDR, net-centricity requires viewing information as an enterprise asset to be shared and as a weapon system to be protected. Finally, the QDR introduced the concept of the 21^st Century Total Force, which explicitly highlights the contractor’s role in support of the Department of Defense in an integrated long-term context.

Increased Spending on Intelligence Gathering and Information Sharing. The terrorist attacks of September 11, 2001 and subsequent events (especially the asymmetric warfare being waged in the Global War on Terror) have intensified the federal government’s commitment to strengthen our country’s military, intelligence, and homeland security capabilities and increased the need for information technology capable of supporting these functions. We believe intelligence agencies will increase demand for data and text mining solutions to enable them to extract, analyze, and present data gathered from the massive volumes of information available through open sources such as the Internet. This increased focus on national security, homeland security, and intelligence has also reinforced the need for interoperability among the many disparate information technology systems

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throughout the federal government. We believe the Department of Homeland Security and the intelligence agencies are increasingly interested in enterprise systems that enable better coordination and communication within and among agencies and departments.

Increasing Reliance on Technology Service Providers. The demand for technology service providers is expected to increase due to the need for federal agencies to maintain core operational functions while the available technical workforce shrinks. The National Academy of Public Administrators estimates that approximately 50.0% of the federal government information technology workforce are near eligibility to retire and that there will be a shortage of technically-skilled replacements. Given the difficulty the federal government has experienced in hiring and retaining skilled technology personnel in recent years, we believe the federal government will need to rely heavily on technology service providers that have experience with government legacy systems, can sustain mission-critical operations and have the required government security clearances to deploy qualified personnel in classified environments.

Continuing Impact of Federal Procurement Reform. In recent years, federal agencies have had increased access to alternative choices in their contract acquisition vehicles—such as indefinite delivery/indefinite quantity contracts (ID/IQs), Government Wide Acquisition Contracts (GWACs), the General Services Administration (GSA) schedule and agency specific Blanket Purchase Agreements (BPAs). These choices have created a market-based environment in government procurement. The environment has increased contracting flexibility and provides government entities access to multiple channels to contractor services. Contractors’ successful past performance, as well as technical capabilities and management skills, remain critical elements of the award process. We believe the increased flexibility associated with the multiple channel access, such as ID/IQs, GWACs, GSA schedule contracts and BPAs, will result in the continued utilization of these contracting vehicles in the future, and will facilitate access to service providers to meet the increased demand for, and delivery of, required services and solutions.

Our Solutions and Services

We deliver comprehensive information technology, technical and other services and solutions for mission-critical, enterprise information technology and communication systems, primarily in support of National Security programs for the Intelligence Community and Department of Defense. Our solutions include the following services offerings, often delivered in combination over an extended period of time in support of long-term programs:

Our offerings fall into one or more of three basic categories: Secure Systems and Infrastructure; Information Technology; and Systems Engineering.

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Secure Systems and Infrastructure Solutions

We provide a broad range of solutions to enhance systems and network availability and mission-critical performance of our customers’ hardware, software, computer network and telecommunication assets and operations, including the following.

Intelligence Operations and Analysis Support. We provide services for strategic and tactical intelligence systems, networks and facilities in support of the Intelligence Community and Department of Defense. To support classified systems and facilities designed to collect, analyze, process and report on various intelligence sources, we develop and integrate collection and analysis systems and techniques. Our intelligence-related services also include the design, rapid development and prototyping, integration and management of real-time signal processing systems. We also provide support to the development and application of analytical techniques to counter-terrorist operations. Our offerings also include the provision of subject matter expert analysts who work directly with the Intelligence Community and Department of Defense customers to produce long-term classified and unclassified research/analytic reporting, as well as provide real-time analytic support for ongoing intelligence operations.

Secrecy Management and Program Security Architecture. We provide secrecy management and security infrastructure services for highly classified programs, including intelligence operations and military programs. Due to the highly sensitive and classified nature of these programs, opportunities are often limited to a select number of providers that possess the requisite capabilities, qualifications and special access clearances. We provide secrecy and security services including vulnerability assessment, exposure analysis, secrecy architecture design, security policy development and implementation, lifecycle acquisition program security, system security engineering, security awareness and training, comprehensive security support services, and technical certification and accreditation services.

For example, we provide integrated security support for the Joint Strike Fighter (JSF) Program. With numerous highly classified technologies incorporated in its design and international content in both its development and its usage, the JSF Program presents the most complex security problem set of any weapon system in our nation’s history. We provide a complete range of integrated security services to the JSF Program Office, including physical, personnel, and cyber security disciplines, as well as in-depth support to international disclosure controls. Our established performance in security architecture development and critical information protection, and our security and risk management methodologies, establish a framework for lifecycle JSF program protection that encompasses all security disciplines.

Information Assurance. We provide comprehensive lifecycle information assurance/security support services to the Department of State, the Department of Justice and agencies in the Intelligence Community. Our services include around the clock intrusion detection and network monitoring, cyber security incident response, network security design, architecture and engineering, certification and accreditation, information assurance training and awareness support, policy review and reporting, compliance auditing, and cyber threat analysis and vulnerability analysis. In 2005, our State Department customer, which supports a 50,000 user population operating in 260 locations worldwide on classified and unclassified networks, was awarded the prestigious National Security Agency sponsored Frank R. Rowlett Award for excellence in information assurance for efforts directly supported by our personnel.

Communication Systems and Infrastructure Support. We design, develop, modify and maintain secure communication systems and network infrastructures. This process involves evaluating industry standards, systems architectures and applications in order to recommend and develop technology solutions and integrate them into a customer’s secure communication systems. We also procure, install and test new voice, data and video communication systems.

For example, we operate regional support centers in the United States, Iraq, Afghanistan, Germany, Korea, Kuwait, Bosnia and elsewhere for intelligence, electronic warfare and related critical missions. We perform

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systems and network troubleshooting, maintenance, repair and installation, as well as integration and testing of electronic, electrical and mechanical equipment designed for vehicular, airborne and portable platforms. Our personnel stationed at these regional support centers have supported every major military deployment since 1990. Beginning with Desert Storm and currently for Iraqi Freedom, our personnel have provided Command, Control, Communications, Computers and Intelligence (C4I) systems operations and maintenance support to deployed units in hostile environments. As part of other overseas activities, we have personnel deployed at locations in Afghanistan, and Kyrgyzstan in support of Air Force operations.

Information Technology Solutions

We provide a broad range of information technology solutions to our customers, including the following.

Enterprise Systems Engineering. We provide network architecture planning and implementation services and systems engineering services in support of enterprise-wide network infrastructures and components that include LAN/WAN architectures, messaging architectures, network management solutions, directory services architecture, and web hosting. These services are provided within secure environments requiring the application of multi-level security policies across the enterprise. For example, we developed and implemented a scalable enterprise-wide network and messaging infrastructure accredited to meet Director of Central Intelligence Directive 6/3 for Protection Level 3 in support of an Intelligence Community customer. Additionally, we provide enterprise systems engineering services to include LAN/WAN, messaging, and e-mail infrastructure architecture and implementation to an Intelligence Community customer.

Information Operations. We provide customers in the Department of Defense and Intelligence Community a wide range of services in the areas of computer forensic analysis, cyber defense, intrusion operations, and network monitoring operations. We perform full-scope digital analysis including advanced data mining analysis, atypical data recovery techniques, and data extraction. We conduct advanced computer network operations analysis including the reverse engineering of network protocols, applications, and operating systems. We also provide custom internet enumeration and analysis services and full lifecycle support for internet access architectures.

For example, in support of a customer, we developed and staffed a national level computer forensic laboratory and provided a broad spectrum of subject matter expertise, including the following:

We played a crucial role in the successful establishment of a national level computer forensic laboratory and provided advanced forensics support.

Enterprise Application Solutions. We design, develop, implement, test, maintain and web-enable software applications for our customers’ information systems and network infrastructures. We provide comprehensive e-commerce services, including web development efforts that focus on designing and maintaining scalable, interoperable, reliable and portable end-to-end information management solutions. We apply these capabilities to critical customer missions requiring multi-layered security within the application in order to improve information sharing and collaboration.

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For example, we developed a state-of-the-art analytic environment that provides access to regional, national and international information with appropriate security level access controls providing direct operational support to time sensitive counterterrorism activities in support of an Intelligence Community customer.

We also developed the major portions of the Homeland Security Information Network (HSIN), which the Department of Homeland Security uses to allow all states, major urban areas, counties and certain foreign government allies to collect, share and disseminate information to combat terrorism. We based HSIN on the Joint Regional Information Exchange System (JRIES), a technology solution that we developed for the Defense Intelligence Agency. HSIN is a secure, around the clock, web-based, real-time collaborative tool that has interactive connectivity with the Department of Homeland Security operations center. This secure system significantly enhances the ability of users to exchange real-time threat information at the sensitive-but-unclassified level. In 2005, HSIN was utilized to support rescue and relief efforts in the aftermath of hurricane Katrina.

Systems/Network Maintenance Services. We have extensive experience in maintaining a wide range of information management resources for our customers. We perform comprehensive systems administration, including around the clock support for continuous mission operations. For example, for the Army, we provide systems administration and help desk functions at a domestic location for a command and management system, as well as help desk functions in an overseas remote location that supports 1,500 users. For this customer, we also provide on-site support for the command and management system workstations and networks located throughout countries in Central and South America.

Systems Engineering Solutions

We offer our customers a broad range of systems engineering solutions, including the following.

Systems Engineering Services. We perform comprehensive systems engineering services to analyze and develop solutions for customer hardware and software requirements. We also evaluate existing system designs to determine if performance enhancements or cost savings can be derived through the integration of current technologies. Since 1968, our engineers and scientists have been providing critical acoustic systems engineering support to the Navy that includes data acquisition and analysis, model instrumentation and maintenance, and program and logistics support. Our personnel have performed acoustic testing for every operational Navy combatant—both surface and submarine. Our support to the Navy also involves data acquisition and recording technology, advanced signal processing and sonar systems engineering analysis. We also support combat identification systems development, and provide systems engineering and technical services that support the design and installation of communication, intelligence, electronic warfare and information systems aboard Navy and Coast Guard ships and at shore-based facilities.

Testing and Evaluation. We test complex and mission-critical hardware and software systems used by the Army, Navy and NASA, with many of these customer relationships spanning more than three decades. We have played key roles in improving the performance, reliability, maintainability, supportability and weapons effectiveness of all Navy in-service rotary and fixed wing platforms, including the F/A-18E/F Super Hornet, and their associated ordnance. We are participating in the development of plans for testing and evaluating the Joint Strike Fighter and the Multi-Mission Maritime Aircraft.

We have supported the NASA Goddard Space Flight Center for more than 30 years as the principal contractor responsible for providing comprehensive integration, environmental test engineering and operations support for systems such as the Hubble Space Telescope. Our space payload test and integration services have supported every in-house earth orbit program since 1971. We conduct a broad range of tests, including structural, acoustics, vibration, space simulation and electromagnetic tests, to certify that all flight hardware can withstand the extreme conditions of space flight. We have been recognized within Goddard and the NASA community for our test, integration, transportation and launch site support.

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Independent Validation and Verification. We perform tests to certify that new systems or upgraded systems operate in accordance with their design requirements. For example, we have performed certification services for aircraft weapon systems in support of U.S. Naval Air Systems Command programs.

Our Growth Strategy

Our objective is to grow our business profitably as a premier provider of comprehensive information technology and technical services solutions to the federal government market. Our strategies for achieving this objective include the following.

Expand Our Customer Base. We intend to capitalize on our long-term relationships with our customers and our reputation within the Intelligence Community, Department of Defense and other government agencies to attract new customers and to cross-sell our broad array of solutions to our existing customers. Under the “best value” contracting process that has resulted from reforms in the government process, past performance and technical approach are key factors that the government may consider when evaluating competitive bids. Based on our long-term support to numerous customers, we believe we have a successful past performance track record and have demonstrated technical expertise that gives us credibility with these customers and enhances our ability to be successful in bidding on follow-on contracts and in competing for new programs of both existing and new customers. As customers seek a “single integrator solution” approach, we believe that we have sufficient experience and expertise to support such programs for current and new customers. Because our personnel are on-site with our customers or work in close proximity to our customers, we develop close relationships with them and are often able to enhance our customers’ operations by rapidly identifying and developing solutions for customer-specific requirements.

Target High Growth Segments of the Market. We believe the projected growth in government information technology and technical services spending will present opportunities for development and delivery of advanced technology solutions for enterprise applications and information systems. We intend to expand our service offerings in high growth program areas. In particular, we intend to focus on providing new or improved solutions in information assurance, including cyber security and homeland defense programs, and other secure systems and infrastructure solutions in support of National Security programs that support the Global War on Terror and ongoing operations in active theaters of military and intelligence operations, such as Iraq and Afghanistan. We also plan to continue to target customers seeking to improve their IT infrastructures and systems, especially those charged with building and operating enhanced web-based collaboration/sharing platforms. We have also identified information assurance and homeland defense programs as targeted growth areas.

Attract and Retain Highly Skilled and Highly Cleared Personnel. We intend to continue to attract and retain skilled professionals, including engineers, scientists, analysts, technicians and support specialists, to ensure that we have the capabilities to fulfill our customers’ requirements. We target candidates who have served in the military or as civilian experts in the Intelligence Community and Department of Defense, as well as those who are leading specialists in their technology disciplines. We believe we can continue to retain our employees by offering competitive compensation and incentive plans, opportunities for career growth through company-supported education programs and diverse, challenging assignments at over 180 locations worldwide. As of December 31, 2005, over 75% of our workforce possess clearances and over 50% possess Top Secret or above level clearances.

Leverage Intellectual Property to Provide Complete Technology Solutions. We intend to leverage our internally developed intellectual property to provide complete technology solutions and generate incremental revenue opportunities across our service offerings. For example, we have implemented our NetWitness product, our integrated network forensic solution, into several intelligence agencies where we previously provided only technology services.

Pursue Strategic Acquisitions. We plan to enhance our internal growth by selectively pursuing strategic acquisitions of businesses that can cost-effectively broaden our domain expertise and service offerings and allow us

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to establish relationships with new customers. We have acquired six companies since our IPO in February 2002, accelerating our overall revenue growth. We are focused primarily on acquiring businesses that provide value-added solutions for the Intelligence Community and Department of Defense, but we will also consider opportunities to acquire other businesses where we can leverage our reputation and experienced management team.

Our Customers

Our customers consist primarily of U.S. federal government intelligence, military and civilian agencies We have successful, long-standing relationships with our customers, having supported many of them for 15 to 30 years. Some of our representative customers include:

We derive the vast majority of our revenues from our federal government customers, consisting primarily of customers in the Intelligence Community and Department of Defense.

Our federal government customers typically exercise independent contracting authority, and multiple offices or divisions within an agency or department may directly, or through a prime contractor, use our services as a separate customer so long as that customer has independent decision-making and contracting authority within its organization. For example, under a blanket purchasing agreement with one of the Army’s contracting agencies, program managers throughout the Army and from other services and defense agencies are able to purchase a wide range of our solutions. One customer, the U.S. Army Lifecycle Management Command (LCMC-HQ) (formerly Communications-Electronic Command Headquarters—CECOM-HQ) accounted for 19.7% of our revenues for the year ended December 31, 2005, and 15.4% of our revenues for the year ended December 31, 2004. No single customer accounted for 10% or more of our revenues for the year ended December 31, 2003. In addition, there were no sales to any customers within a single country (except for the United States) where the sales accounted for 10% or more of our total revenue.

For 2005 and 2004, we derived 18.7% and 14.0%, respectively, of our revenues through relationships with prime contractors, who contract directly with the customer and subcontract to us.

Foreign Operations

We treat sales to U.S. government customers as sales within the United States, regardless of where services are performed. The percentages of total revenues by geographic customer for the last three years were as follows:

Other information relating to our foreign operations is provided in Note 4 to our consolidated financial statements.

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Backlog

At December 31, 2005, our backlog was $2.3 billion, of which $467 million was funded backlog. At December 31, 2004, our backlog was $1.6 billion, of which $444 million was funded backlog. Backlog and funded backlog represent estimates that we calculate on the basis described below. We expect that approximately 35% to 45% of our total backlog will be recognized as revenues prior to December 31, 2006.

We define backlog as our estimate of the remaining future revenues from existing signed contracts, assuming the exercise of all options relating to such contracts and including executed task orders issued under GSA schedule contracts. This includes an estimate of revenues for solutions that we believe we will be asked to provide in the future under the terms of executed multiple-award contracts for which we are not the sole provider, meaning that the customer could turn to other companies to fulfill the contract. It also includes an estimate of revenues from indefinite delivery, indefinite quantity contracts, which specify a maximum, but only a token minimum, amount of goods or services that may be provided under the contract. Backlog does not include the value for contracts where we have been given permission by the customer to begin or continue working, but where a formal contract or contract extension has not yet been signed.

We define funded backlog to be the portion of backlog for which funding currently is appropriated and allocated to the contract by the purchasing agency or otherwise authorized for payment by the customer upon completion of a specified portion of work. Our funded backlog does not include the full value of our contracts, because Congress often appropriates funds for a particular program or contract on a yearly or quarterly basis, even though the contract may call for performance that is expected to take a number of years.

Changes in the amount of our backlog and funded backlog result from potential future revenues from the execution of new contracts or the extension of existing contracts, reductions from contracts that end or are not renewed, reductions from the early termination of contracts, and adjustments to estimates for previously included contracts. Changes in the amount of our funded backlog also are affected by the funding cycles of the government. Our estimates of future revenues are necessarily inexact and the receipt and timing of any of these revenues is subject to various contingencies, many of which are beyond our control. The actual accrual of revenues on programs included in backlog and funded backlog may never occur or may change because a program schedule could change, a program could be canceled, a contract could be modified or canceled, an option that we have assumed would be exercised is not exercised, or initial estimates regarding the level of solutions that we may provide could prove to be wrong. For the same reason, we believe that period-to-period comparisons of backlog and funded backlog are not necessarily indicative of future revenues that we may receive.

Employees

As of December 31, 2005, we had approximately 6,000 employees, including approximately 300 part-time and temporary full-time employees. Over 700 employees were located outside of the United States.

Approximately 200 of our employees, all of whom are located at NASA’s Goddard Space Flight Center, are represented by the International Brotherhood of Electrical Workers union under a collective bargaining agreement. We have not experienced any work stoppage or strike by these employees and believe our relations with the union and our employees to be good.

Patents, Trademarks, Trade Secrets and Licenses

We own two patents in the United States and two patents in Canada. While we believe these patents are valid, we do not consider our business to be dependent on the protection of these patents in any material way.

We presently own 18 registered trademarks and service marks in the U.S., and we have three registered copyrights. Because most of our business involves providing services to federal government customers, our operations generally are not substantially dependent upon obtaining and/or maintaining copyright or trademark protections, although our operations make use of such protections.

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We license third party software, data and products. With the exception of our enterprise resource planning software, our operations are not materially dependent on such licenses.

We maintain a number of trade secrets that contribute to our success and competitive distinction and endeavor to accord such trade secrets protection adequate to ensure their continuing availability to us. While retaining protection of our trade secrets and vital confidential information is important, we are not materially dependent on maintenance of any specific trade secret or group of trade secrets.

We also enter into confidentiality and intellectual property agreements with our employees, which contain provisions that require them to disclose any inventions created during employment, convey all rights to inventions to us, and restrict the distribution of proprietary or confidential information.

Cyclicality

Expenditures by our customers tend to vary in cycles that reflect overall economic conditions and customer mission requirements, as well as budgeting and buying patterns. Our revenue has in the past been, and may in the future be, materially affected by a decline in the defense or other intelligence budgets or in the economy in general. Such future declines could alter our current or prospective customers’ spending priorities and budget cycles, or extend our sales cycle.

Competition

Our key competitors currently include divisions of large defense contractors such as BAE Systems, plc, Computer Sciences Corporation, General Dynamics, Lockheed Martin Corporation, Northrop Grumman Corporation, and Science Applications International Corporation, as well as a large number of smaller U.S. government contractors with specialized capabilities, such as CACI, Booz Allen & Hamilton and SRA International. Because of the diverse requirements of U.S. government customers and the highly competitive nature of large procurements, corporations frequently form teams to pursue contract opportunities. The same companies listed as competitors will, at times, team with us or subcontract to us in the pursuit of new business. We believe that the major competitive factors in our market are distinctive technical competencies, successful past contract performance, intelligence and military work experience, price of services, reputation for quality and key management with domain expertise.

2005 Acquisition

Gray Hawk Systems, Inc.—On May 31, 2005, we completed the acquisition of 100 percent of the outstanding shares of Gray Hawk Systems, Inc. (“Gray Hawk”). Gray Hawk provides a broad range of intelligence-related services to the homeland security, law enforcement, Intelligence Community and the Department of Defense markets. The acquisition was consummated pursuant to an Agreement and Plan of Merger, dated May 3, 2005, which provided for the merger of a wholly owned subsidiary of ManTech with and into Gray Hawk, with Gray Hawk surviving the merger and becoming a wholly owned subsidiary of ManTech (“ManTech Gray Hawk”).

We believe the Gray Hawk acquisition further solidifies our position as a supplier of services in the high-end intelligence market. It expands our presence in homeland security related missions and compliments our high-end offerings for the Intelligence Community and Department of Defense. Gray Hawk’s capabilities round-out our skills in the end-to-end, intelligence information processing cycle, and give us access to new markets in national defense agencies which we believe will become increasingly important as the Intelligence Reform Act of 2004 continues to unfold.

The purchase price for the Merger was $101.8 million in cash, which included transaction costs of $0.3 million. The purchase price included the full payment of Gray Hawk’s outstanding debt, repurchase of employee stock options by Gray Hawk, transaction costs and other related transaction expenses. Pursuant to the Merger

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Agreement, and as security for the Gray Hawk shareholders’ indemnification obligations, an escrow account in an amount equal to 10% of the adjusted purchase price has been established for a period of one year following the closing of the Merger, which is to be used to satisfy certain indemnification obligations of the shareholders of Gray Hawk.

2004 Acquisition

Acquisition of Certain Assets from Affiliated Computer Services, Inc.—In furtherance of our strategic initiative to expand and enhance our support of the U.S. Air Force, on February 27, 2004, we acquired certain assets from Affiliated Computer Services, Inc. (ACS), a provider of systems engineering, network administration, program management, and communications systems support to Department of Defense customers. The assets acquired from ACS included contracts providing support to the U.S. Air Force Electronic Systems Center’s Information Technology Services Program. Services provided through these contracts include information technology services such as program management, systems engineering, network engineering and administration, test and evaluation, and data management. The purchase price of this acquisition was $6.5 million. On June 1, 2004, we acquired additional assets from ACS for $1.5 million. The assets acquired from ACS include contracts for providing support to NATO.

2003 Acquisitions

Integrated Data Systems Corporation—On February 28, 2003, we acquired 100 percent of the outstanding common shares of Integrated Data Systems (IDS) for a cash purchase price of $62.7 million, net of cash on hand of $2.8 million. The cash purchase price excluded $1.0 million of acquisition-related costs and was subject to an earnout provision. Founded in 1990, IDS delivers technology solutions and products in four core areas: software development, systems engineering/networking, information assurance, and government acquisition/procurement support software. IDS has developed secure, advanced messaging and collaboration applications and solutions in support of a wide variety of national security networks and systems. IDS is also one of Microsoft’s leading certified partners supporting U.S. government classified Intelligence Community programs. Many of the IDS employees have military or intelligence experience and high-level clearances.

MSM Security Services, Inc.—On March 5, 2003, we acquired 100 percent of the outstanding common shares of MSM Security Services, Inc. (MSM), a Maryland-based provider of Personnel Security Investigation (PSI) services to the U.S. government. The cash purchase price was approximately $4.9 million, of which $2.2 million in cash was paid to MSM shareholders and $2.7 million was used to repay existing MSM debt. The cash purchase price excludes $0.2 million of acquisition-related costs and is subject to an earnout provision. MSM specializes in PSI services for the U.S. government, having completed over 250,000 background investigations since its founding in 1978. MSM has active investigation contracts to support the U.S. Customs Service, the Office of Personnel Management, the Department of State, the Intelligence Community, and other federal government agencies.

In February 2005, we reached a final corporate determination to exit the personnel security investigation (PSI) services business and discontinue operations at our MSM subsidiary. We reached the determination to sell our MSM subsidiary after we concluded that the MSM business no longer furthered our long-term strategic objectives. Currently, we intend to sell MSM as a going-concern and are in discussions with potential buyers. We expect to complete the sale or other disposition of the MSM operations by the end of the second quarter 2006. At December 31, 2005, we recorded a loss accrual of $3.6 million on the valuation of these assets based on offers received from potential buyers in early 2006. The loss accrual reflects the write-off of intangible assets including goodwill, net of taxes and a valuation allowance of $1.3 million for deferred state income tax assets. For further information, see Note 16 to the Consolidated Financial Statements in Item 8.

Company Information Available on the Internet

Our internet address is www.mantech.com. We make available free of charge on our internet site our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and any amendments to

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those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC.

ITEM 1A. Risk Factors

We depend on contracts with the U.S. federal government for substantially all of our revenues. If our relationships with the federal government are harmed, our business could be adversely affected.

We expect that federal government contracts will continue to be the primary source of our revenues for the foreseeable future. We derived approximately 98% of our revenues from our federal government customers, (consisting primarily of customers in the Intelligence Community, the Departments of Defense, State, Homeland Security and Justice, and other U.S. federal government agencies) in each of the last two years. Our business, prospects, financial condition or operating results could be materially harmed if

Among the key factors in maintaining our relationships with federal government agencies are our performance on individual contracts and task orders, the strength of our professional reputation and the relationships of our senior management with our customers.

Federal government spending priorities may change in a manner that harms our business.

Our business depends upon continued federal government expenditures on intelligence, defense and other programs that we support. These expenditures have not remained constant over time. For example, the overall U.S. defense budget declined for periods of time in the late 1980s and the early 1990s. While spending authorizations for intelligence and defense-related programs by the government have increased in recent years, and in particular after the September 11, 2001 terrorist attacks, future levels of expenditures and authorizations for these programs may decrease, remain constant or shift to programs in areas where we do not currently provide services. Our business, prospects, financial condition or operating results could be materially harmed by the following

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Federal government contracts contain provisions that are unfavorable to us.

Federal government contracts contain provisions, and are subject to laws and regulations, that give the government rights and remedies not typically found in commercial contracts. These provisions may allow the government to

If the government terminates a contract for convenience, we may recover only our incurred or committed costs, settlement expenses and profit on work completed prior to the termination. If the government terminates a contract for default, we may not recover even those amounts, and instead may be liable for excess costs incurred by the government in procuring undelivered items and services from another source. We may experience performance issues on some of our contracts. We may receive show cause or cure notices under contracts that, if not addressed to the government’s satisfaction, could give the government the right to terminate those contracts for default or to cease procuring our services under those contracts in the future.

We may be exposed to liabilities or losses from operations that we have or will discontinue or otherwise sell, including our MSM subsidiary.

In February 2005, we reached a final corporate determination to exit the personnel security investigation (PSI) services business and discontinue operations at our MSM subsidiary. Currently, we intend to sell MSM as a going-concern. We have engaged in discussions with potential buyers, and we expect to complete the sale or other disposition of the MSM operations by the end of the second quarter of 2006. However, we cannot assure you that we will complete a transaction under the terms currently being discussed with such parties, or at all. Similarly, we may incur unanticipated additional costs in connection with the sale or disposition of MSM. If we are not able to sell or dispose of MSM on the terms currently contemplated, our business, prospects, financial condition or operating results could be harmed.

In recent years, we have sold or wound down the operations of other businesses as well.

For more information on these discontinued operations, please see Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations—Discontinued Operations and Note 16 to our consolidated financial statements. Our consolidated financial statements reflect, under the heading “Discontinued Operations,” our estimate of the net losses we expected from these operations through the date we estimated they would be disposed, and all losses expected to be realized upon the disposal of these operations. Even after the disposition of these businesses, we may continue to be exposed to some liabilities arising from their prior operations. Additionally, when we sell one of our subsidiaries, the operative contractual agreement may contain provisions that require us to indemnify the purchaser for certain liabilities that arose prior to the sale date but that are discovered afterwards. Even though these liabilities are often capped, until the indemnification period expires, we may continue to be exposed to such liabilities.

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If we fail to comply with complex procurement laws and regulations, we could be liable for various penalties or sanctions.

We must comply with laws and regulations relating to the formation, administration and performance of federal government contracts. These laws and regulations affect how we conduct business with our federal government contracts. In complying with these laws and regulations, we may incur additional costs, and non-compliance may also allow for the assignment of additional fines and penalties, including contractual damages. Among the more significant laws and regulations affecting our business are the following:

Along with agency regulations supplemental to the Federal Acquisition Regulations, comprehensively regulate the formation, administration and performance of federal government contracts

Requires certification and disclosure of all cost and pricing data in connection with contract negotiations

Imposes accounting requirements that govern our right to reimbursement under certain cost-based federal government contracts

Our contracting agency customers periodically review our performance under and compliance with the terms of our federal government contracts. We also routinely perform internal reviews. As a result of these reviews, we may learn that we are not in compliance with all of the terms of our contracts. If a government review or investigation uncovers improper or illegal activities, we may be subject to civil or criminal penalties or administrative sanctions, including

If we fail to comply with these laws and regulations, we may also suffer harm to our reputation, which could impair our ability to win awards of contracts in the future or receive renewals of existing contracts. If we are subject to civil and criminal penalties and administrative sanctions or suffer harm to our reputation, our current business, future prospects, financial condition, or operating results could be materially harmed. In addition, we are subject to industrial security regulations of the Department of Defense and other federal agencies that are designed to safeguard against unauthorized release or access to classified information by foreign nationals. The government may also reform our procurement practices or adopt new contracting rules and regulations, including cost accounting standards, that could be costly to satisfy or that could impair our ability to obtain new contracts.

Unfavorable federal government audit results could subject us to penalties or sanctions, and could harm our reputation and relationships with our customers and impair our ability to win new contracts.

The Defense Contract Audit Agency (DCAA) and other government agencies routinely audit and investigate government contracts. These agencies review a contractor’s performance on its contract, cost structure and

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compliance with applicable laws, regulations and standards. The DCAA also reviews the adequacy of, and a contractor’s compliance with, its internal control systems and policies, including the contractor’s purchasing, property, estimating, compensation and management information systems. Any costs found to be improperly allocated to a specific contract will not be reimbursed, while such costs already reimbursed must be refunded. Therefore, a DCAA audit could materially affect our competitive position and result in a substantial adjustment to our revenues. If a government audit uncovers improper or illegal activities, we may be subject to civil and criminal penalties and administrative sanctions, including termination of contracts, forfeiture of profits, suspension of payments, fines and suspension or debarment from doing business with federal government agencies. In addition, we could suffer serious harm to our reputation if allegations of impropriety were made against us.

We derive significant revenues from contracts awarded through a competitive bidding process.

We expect that a significant portion of our future business will be awarded through competitive bidding. Competitive bidding presents a number of risks, including

We may not be provided the opportunity in the near term to bid on contracts that are held by other companies and are scheduled to expire if the government extends the existing contract. If we are unable to win particular contracts that are awarded through the competitive bidding process, we may be unable to operate in the market for services that are provided under those contracts for a number of years. If we are unable to consistently win new contract awards over any extended period, our business and prospects will be adversely affected.

The government may terminate our federal government contracts at any time.

We derive substantially all of our revenue from federal government contracts that may span one or more base years and one or more option years. The option periods typically cover more than one-half of the contract’s duration. Federal government agencies generally have the right not to exercise these option periods. Additionally, federal government contracts typically contain provisions permitting a government client to terminate the contracts for its convenience. A decision not to exercise option periods or a decision to terminate contracts could result in a substantial adjustment to our revenues and reduce the profitability of these contracts to us.

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We may not accurately estimate the expenses, time and resources necessary to satisfy our contractual obligations.

We enter into three types of federal government contracts for our services: cost-plus, time-and-materials and fixed-price. For our last two fiscal years, we derived revenue from such contracts as follows:

Under cost-plus contracts, we are reimbursed for allowable costs and paid a fee, which may be fixed or performance-based. To the extent that the actual costs incurred in performing a cost-plus contract are within the contract ceiling and allowable under the terms of the contract and applicable regulations, we are entitled to reimbursement of our costs, plus a profit. However, if our costs exceed the ceiling or are not allowable under the terms of the contract or applicable regulations, we may not be able to recover those costs. Under time-and-materials contracts, we are reimbursed for labor at negotiated hourly billing rates and for certain expenses. We assume financial risk on time-and-material contracts because we assume the risk of performing those contracts at negotiated hourly rates. Under fixed-price contracts, we perform specific tasks for a fixed price. Compared to cost-plus contracts, fixed-price contracts generally offer higher margin opportunities, but involve greater financial risk because we bear the impact of cost overruns and bear the risk of underestimating the level of effort required to perform the contractual obligations, which could result in increased costs and expenses. Our profits could be adversely affected if our costs under any of these contracts exceed the assumptions we used in bidding for the contract.

If we acquire other businesses, our contract mix may change.

We may not receive the full amount authorized under our contracts and we may not accurately estimate our backlog.

As of December 31, 2005, our estimated contract backlog totaled approximately $2.3 billion, of which approximately $467 million was funded. Backlog is our estimate of the remaining future revenues from existing signed contracts, and assume the exercise of all options relating to such contracts. Backlog also includes estimates of revenues for solutions that we believe we will be asked to provide in the future under the terms of executed multiple-award contracts, and estimates of revenues from indefinite delivery indefinite quantity (IDIQ) contracts.

Our estimates of future revenues are necessarily inexact, and the receipt and timing of any of these revenues is subject to various contingencies, many of which are beyond our control. The actual accrual of revenues on programs included in backlog and funded backlog may never occur, or may change as a result of a program schedule change, a program cancellation, a contract modification, an option that we had assumed would be exercised not being exercised, or an inaccurate estimate regarding the level of solutions that we are asked to provide.

There can be no assurance that our backlog will result in actual revenue in any particular period, or at all, or that any contract included in backlog will be profitable. There is a higher degree of risk in this regard with respect to unfunded backlog. In recent years we have derived a significant percentage of our revenues under GSA schedule contracts and task orders, which are procurement vehicles under which government agencies may, but are not required to, purchase professional services or products. Our estimates are based on our experience using such vehicles and similar contracts. However, there are no assurances that all, or any, of such estimated contract value will be recognized as revenue.

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Many of our federal government customers execute their procurement budgets through multiple award contracts under which we are required to compete for post-award orders, or for which we may not be eligible to compete, potentially limiting our ability to win new contracts and increase revenue.

Budgetary pressures and reforms in the procurement process have caused many U.S. federal government customers to increasingly purchase goods and services through multiple award IDIQ contracts, General Services Administration (GSA) Schedule contracts and other multiple award and/or Government Wide Acquisition Contracts (GWAC) vehicles. These contract vehicles have resulted in increased competition and pricing pressure requiring that we make sustained post-award efforts to realize revenues under the relevant contract. There can be no assurance that we will continue to increase revenues or otherwise sell successfully under these contract vehicles. Our failure to compete effectively in this procurement environment could harm our operating results.

Failure to maintain strong relationships with other contractors could result in a decline in our revenues.

In 2005 and 2004, we derived 18.7% and 14.0% of our revenues, respectively, from contracts in which we acted as a subcontractor to other contractors or to joint ventures that we and other contractors formed to bid on and execute particular contracts or programs. We expect to continue to depend on relationships with other contractors for a portion of our revenues for the foreseeable future. Our business, prospects, financial condition or operating results could be harmed if other contractors eliminate or reduce their subcontracts or joint venture relationships with us, either because they choose to establish relationships with our competitors or because they choose to directly offer services that compete with our business, or if the government terminates or reduces these other contractors’ programs or does not award them new contracts.

If we are unable to manage our growth, our business could be adversely affected.

Sustaining our growth has placed significant demands on our management, as well as on our administrative, operational and financial resources. To continue to manage our growth, we must continue to improve our operational, financial and management information systems and expand, motivate and manage our workforce. If we are unable to manage our growth while maintaining our quality of service and profit margins, or if new systems that we implement to assist in managing our growth do not produce the expected benefits, our business, prospects, financial condition or operating results could be adversely affected.

We may not be successful in identifying acquisition candidates, and we may undertake acquisitions that could increase our costs or liabilities or be disruptive.

One of our key operating strategies is to selectively pursue acquisitions. We have made a number of acquisitions in the past, are currently evaluating a number of potential acquisition opportunities, and will consider other acquisitions in the future. We may not be able to identify suitable acquisition candidates at prices we consider appropriate, or finance acquisitions on terms that are satisfactory to us. If we do identify an appropriate acquisition candidate, we may not be able to successfully negotiate the terms of an acquisition, finance the acquisition or, if the acquisition occurs, integrate the acquired business into our existing business. Negotiations of potential acquisitions and the integration of acquired business operations could disrupt our business by diverting management away from day-to-day operations. Acquisitions of large businesses or other material operations may require additional debt or equity financing, resulting in additional leverage or dilution of ownership.

If we are unable to successfully integrate companies that we acquire, our revenue and operating results could suffer. The integration of such businesses into our operations may result in unforeseen operating difficulties (including incompatible accounting and information management systems), may absorb significant management attention and may require significant financial resources that would otherwise be available for the ongoing development or expansion of our business. The difficulties of integration may be increased by the necessity of coordinating geographically dispersed organizations, integrating personnel with disparate business backgrounds and combining different corporate cultures. In certain acquisitions, federal acquisition regulations

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may require us to enter into government novation agreements, a potentially time-consuming process. We also may not realize cost efficiencies or synergies that we anticipated when selecting our acquisition candidates. We may experience attrition, including, but not limited to, key employees of the acquired companies, during and following the integration of the acquired businesses that could reduce our future revenue. In addition, we may need to record write-downs from future impairments of intangible assets, which could reduce our future reported earnings. At times, acquisition candidates may have liabilities or adverse operating issues that we fail to discover through due diligence prior to the acquisition. In particular, to the extent that prior owners of any acquired businesses or properties failed to comply with or otherwise violated applicable laws or regulations, or failed to fulfill their contractual obligations to the federal government or other clients, we, as the successor owner, may be financially responsible for these violations and failures and may suffer harm to our reputation or otherwise be adversely affected. The discovery of any material liabilities associated with our acquisitions could cause us to incur additional expenses and cause a reduction in our operating profits.

If we fail to recruit and retain skilled employees or employees with the necessary security clearances, we might not be able to perform under our contracts or win new business.

To be competitive, we must have employees who have advanced information technology and technical services skills and who work well with our customers in a government or defense-related environment. These employees are in great demand and are likely to remain a limited resource in the foreseeable future. If we are unable to recruit and retain a sufficient number of these employees, our ability to maintain and grow our business could be negatively impacted. In addition, some of our contracts contain provisions requiring us to commit to staff a program with certain personnel the customer considers key to our successful performance under the contract. In the event we are unable to provide these key personnel or acceptable substitutions, the customer may terminate the contract, and we may not be able to recover certain incurred costs.

We face competition from other firms, many of which have substantially greater resources.

We operate in highly competitive markets and generally encounter intense competition to win contracts. We compete with many other firms, ranging from small, specialized firms to large, diversified firms, many of which have substantially greater financial, management and marketing resources than we do. Our competitors may be able to provide our customers with different or greater capabilities or benefits than we can provide in areas such as technical qualifications, past contract performance, geographic presence, price and the availability of qualified professional personnel. Our failure to compete effectively with respect to any of these or other factors could cause our revenue and operating profits to decline. In addition, our competitors also have established or may establish relationships among themselves or with third parties to increase their ability to address our customers’ needs. Accordingly, it is possible that new competitors or alliances among competitors may emerge.

Mr. Pedersen, our Chairman and Chief Executive Officer, effectively controls our company, and his interests may not be aligned with those of other stockholders.

As of December 31, 2005, Mr. Pedersen owned approximately 45.5% of our outstanding shares of Class A and Class B common stock, and owned or controlled approximately 89.3% of the combined voting power of our stock. Accordingly, Mr. Pedersen controls the vote on all matters submitted to a vote of our stockholders. As long as Mr. Pedersen beneficially owns a majority of the combined voting power of our common stock, he will have the ability, without the consent of our public stockholders, to elect all members of our board of directors and to control our management and affairs. Mr. Pedersen’s voting control may have the effect of preventing or discouraging transactions involving an actual or a potential change of control of the Company, regardless of whether a premium is offered over then-current market prices. Mr. Pedersen will be able to cause a change of control of the Company. Mr. Pedersen could also cause a registration statement to be filed and to become effective under the Securities Act of 1933, thereby permitting him to freely sell or transfer the shares of common stock that he owns. In addition, the interests of Mr. Pedersen may conflict with the interests of other holders of our common stock.

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The loss of any member of our senior management could impair our customer relationships and disrupt the management of our business.

We believe that our success depends in part on the continued contributions of our co-founder, Chairman of the Board of Directors and Chief Executive Officer, George J. Pedersen; our President and Chief Operating Officer, Robert A. Coleman; our Chief Financial Officer, Kevin M. Phillips; our Senior Executive Vice President, Eugene C. Renzi; and other members of our senior management. We rely on our executive officers and senior management to generate business and execute programs successfully. Furthermore, the relationships and reputation that members of our management team have established and maintain with government and military personnel contribute to our ability to maintain good customer relations and to identify new business opportunities. The loss of Mr. Pedersen, Mr. Coleman, Mr. Phillips, Mr. Renzi or any other senior management personnel could impair our ability to identify and secure new contracts, to maintain good customer relationships and otherwise to manage our business.

We may be liable for systems and service failures.

We create, implement and maintain information technology and technical services solutions that are often critical to our customers’ operations, including those of federal, state and local governments. We have experienced and may in the future experience some systems and service failures, schedule or delivery delays and other problems in connection with our work. If our solutions, services, products or other applications have significant defects or errors, are subject to delivery delays or fail to meet our customers’ expectations, we may

In addition to any costs resulting from product warranties, contract performance or required corrective action, these failures may result in increased costs or loss of revenues if they result in customers postponing subsequently scheduled work or canceling or failing to renew contracts.

While many of our contracts with the federal government limit our liability for damages that may arise from negligence in rendering services to our customers, we cannot be sure that these contractual provisions will protect us from liability for damages if we are sued. Furthermore, our errors and omissions and product liability insurance coverage may not continue to be available on reasonable terms or in sufficient amounts to cover one or more large claims, or the insurer may disclaim coverage as to some types of future claims. The successful assertion of any large claim against us could seriously harm our business. Even if not successful, these claims could result in significant legal and other costs and may be a distraction to our management and may harm our reputation.

Covenants in our credit facility may restrict our financial and operating flexibility.

We maintain a credit facility with Citizens Bank of Pennsylvania, KeyBank National Association, Branch Banking and Trust Company of Virginia, Chevy Chase Bank, F.S.B., and Riggs Bank, N.A. Our agreement initially provides for a $125 million revolving credit facility that can be increased to $200 million. The maturity date of the agreement is February 25, 2009. Our credit facility contains covenants that limit or restrict our ability to borrow additional money, merge or consolidate, sell or dispose of assets other than in the ordinary course of business, make acquisitions, enter into related-party transactions, pay dividends, and make certain capital expenditures. Our credit facility also requires us to maintain specified financial covenants relating to asset coverage, fixed charge coverage, and debt coverage ratios. Our ability to satisfy these financial ratios can be affected by events beyond our control, and we cannot assure you that we will meet these ratios. Default under our credit facility could allow the lenders to declare all amounts outstanding to be immediately due and payable. We

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have pledged substantially all of our assets to secure the debt under our credit facility. If the lenders declare amounts outstanding under the credit facility to be due, the lenders could proceed against those assets. Any event of default, therefore, could have a material adverse effect on our business if the creditors determine to exercise their rights. We also may incur future debt obligations that might subject us to restrictive covenants that could affect our financial and operational flexibility, restrict our ability to pay dividends on our common stock or subject us to other events of default.

From time to time we may require consents or waivers from our lenders to permit actions that are prohibited by our credit facility. If our lenders refuse to provide waivers of our credit facility’s restrictive covenants and/or financial ratios, then we may be in default under our credit facility, and we may be prohibited from undertaking actions that are necessary or desirable to maintain and expand our business.

Security breaches in classified government systems could adversely affect our business.

Many of the programs we support and systems we develop, install and maintain involve managing and protecting information involved in intelligence, national security and other classified government functions. While we have programs designed to comply with relevant security laws, regulations and restrictions, a security breach in one of these systems could cause serious harm to our business, damage our reputation and prevent us from being eligible for further work on critical classified systems for federal government customers. Losses that we could incur from such a security breach could exceed the policy limits that we have for errors and omissions or product liability insurance. Damage to our reputation or limitations on our eligibility for additional work resulting from a security breach in one of the systems we develop, install and maintain could materially reduce our revenue.

Our quarterly operating results may fluctuate.

Our quarterly revenues and operating results may fluctuate significantly in the future. A number of factors cause our revenues, cash flow and operating results to vary from quarter to quarter, including

Because a relatively large amount of our expenses are fixed, cash flows from our operations may vary significantly as a result of changes in the volume of services provided under existing contracts and the number of contracts that are commenced, completed or terminated during any quarter. We incur significant operating

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expenses during the start-up and early stages of large contracts, and typically we do not receive corresponding payments in that same quarter. We may also incur significant or unanticipated expenses when a contract expires, terminates or is not renewed.

Payments due to us from federal government agencies may be delayed due to billing cycles or as a result of failures of governmental budgets to gain Congressional and Administration approval in a timely manner. The federal government’s fiscal year ends September 30. If a federal budget for the next fiscal year has not been approved by that date in each year, our clients may have to suspend engagements that we are working on until a budget has been approved. Any such suspensions may reduce our revenue in the fourth quarter of that year or the first quarter of the subsequent year. The federal government’s fiscal year end can also trigger increased purchase requests from clients for equipment and materials. Any increased purchase requests we receive as a result of the federal government’s fiscal year end would serve to increase our third or fourth quarter revenue, but may decrease profit margins for that quarter, as these activities generally may not be as profitable as our typical offerings.

Our business depends upon obtaining and maintaining required security clearances.

Many of our federal government contracts require our employees to maintain various levels of security clearances, and we are required to maintain certain facility security clearances complying with Department of Defense requirements. Obtaining and maintaining security clearances for employees involves a lengthy process, and it is difficult to identify, recruit and retain employees who already hold security clearances. If our employees are unable to obtain or retain security clearances or if our employees who hold security clearances terminate employment with us, the customer whose work requires cleared employees could terminate the contract or decide not to renew it upon its expiration. In addition, we expect that many of the contracts on which we will bid will require us to demonstrate our ability to obtain facility security clearances and perform work with employees who hold specified types of security clearances. To the extent we are not able to obtain facility security clearances or engage employees with the required security clearances for a particular contract, we may not be able to bid on or win new contracts, or effectively rebid on expiring contracts.

Our employees or subcontractors may engage in misconduct or other improper activities, which could cause us to lose contracts.

While we have ethics and compliance programs in place, we are exposed to the risk that employee fraud or other misconduct could occur. Additionally, from time to time we enter into arrangements with subcontractors and joint venture partners to bid on and execute particular contracts or programs; as a result, we are exposed to the risk that fraud or other misconduct or improper activities by such persons may occur. Misconduct by employees, subcontractors or joint venture partners could include intentional failures to comply with federal laws, federal government procurement regulations or the terms of contracts that we receive, falsifying time records or failures to disclose unauthorized or unsuccessful activities to us. These actions could lead to civil, criminal, and/or administrative penalties (including fines, imprisonment, suspension and/or debarment from performing federal government contracts) and harm our reputation. Misconduct by our employees, subcontractors or joint venture partners could also involve the improper collection, handling or use of our customers’ sensitive or classified information, which could result in regulatory sanctions and serious harm to our reputation. We have from time to time experienced occurrences of misconduct and improper activities by our employees, subcontractors or joint venture partners. It is not always possible to deter misconduct by our employees, subcontractors or joint venture partners. Under certain circumstances, conduct of our employees can be imputed to the ManTech subsidiary for which they work and the conduct of ManTech subsidiaries can be imputed to ManTech International Corporation with the consequence that ManTech International Corporation could be subject to sanctions and penalties for actions taken by our subsidiaries and/or the employees of our subsidiaries. The precautions we take to prevent and detect such activity may not be effective in controlling unknown or unmanaged risks or losses, and such misconduct by employees, subcontractors or joint venture partners could result in serious civil or criminal penalties or sanctions or harm to our reputation, which could cause us to lose contracts or cause a reduction in revenue.

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We may be harmed by intellectual property infringement claims.

We may be subject to claims from our employees or third parties who assert that software solutions and other forms of intellectual property that we used in delivering services and solutions to our customers infringe upon intellectual property rights of such employees or third parties. If our vendors, our employees or third parties assert claims that we or our customers are infringing on their intellectual property rights, we could incur substantial costs to defend these claims. In addition, if any of these infringement claims are ultimately successful, we could be required to

Item 1B. Unresolved SEC Staff Comments

We have not received any written comments from the SEC staff regarding our periodic or current reports under the Exchange Act not less than 180 days before the end of our fiscal year that remain unresolved.

Item 2. Properties

Our facilities are leased in close proximity to our customers. Since 1992, we have leased our corporate headquarters office building in Fairfax, Virginia. The lease on this facility expires in March 2010. As of December 31, 2005, we leased 35 additional operating facilities throughout the metropolitan Washington, D.C. area and 28 facilities in other parts of the United States. We also have employees working at customer sites throughout the United States and in other countries. During 2005, we acquired two office buildings (total of 10,780 square feet) and another smaller building on approximately 4.4 acres of land in King George, VA for $2 million. The office buildings are used by Gray Hawk operations. The smaller building is leased to a small commercial business.

The following table provides information concerning certain of our leased properties. No individual lease is material to our business.

We do not anticipate any significant difficulty in renewing our leases or finding alternative space to lease upon the expiration of our leases. Lease expiration dates range from years 2006 through 2015.

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Item 3. Legal Proceedings

We are subject to certain legal proceedings, government audits, investigations, claims and disputes that arise in the ordinary course of our business. Like most large government defense contractors, our contract costs are audited and reviewed on a continual basis by an in-house staff of auditors from the Defense Contract Auditing Agency. In addition to these routine audits, we are subject from time to time to audits and investigations by other agencies of the federal government. These audits and investigations are conducted to determine if our performance and administration of our government contracts are compliant with contractual requirements and applicable federal statutes and regulations. An audit or investigation may result in a finding that our performance, systems and administration is compliant or, alternatively, may result in the government initiating proceedings against us or our employees, including administrative proceedings seeking repayment of monies, suspension and/or debarment from doing business with the federal government or a particular agency, or civil or criminal proceedings seeking penalties and/or fines. Audits and investigations conducted by the federal government frequently span several years.

Although we cannot predict the outcome of these and other legal proceedings, investigations, claims and disputes, based on the information now available to us, we do not believe the ultimate resolution of these matters, either individually or in the aggregate, will have a material adverse effect on our business, prospects, financial condition or operating results.

Item 4. Submission of Matters to a Vote of Security Holders

No matters were submitted to a vote of security holders during the fourth quarter of the year ended December 31, 2005.

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PART II

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

Market Information

Our Class A common stock has been quoted on the Nasdaq National Market under the symbol “MANT” since our initial public offering on February 7, 2002. The following table sets forth, for the periods indicated, the high and low prices of our shares of common stock, as reported on the Nasdaq National Market.

There is no established public market for our Class B common stock.

As of March 1, 2006, there were twenty-seven holders of record of our Class A common stock and four holders of record of our Class B common stock. The number of holders of record of our Class A common stock is not representative of the number of beneficial holders because many of the shares are held by depositories, brokers or nominees.

Dividend Policy

Currently, we intend to retain any earnings for the future operation and growth of our business. In addition, our credit facility restricts us from paying cash dividends to holders of our common stock. As a result, we do not anticipate paying any cash dividends in the foreseeable future. No dividends have been declared on any class of our common stock since our initial public offering in 2002. Any future dividends declared would be at the discretion of our board of directors and would depend, among other factors, upon our results of operations, financial condition and cash requirements, and the terms of our credit facility and other financing agreements at the time such payment is considered.

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Securities Authorized for Issuance under Equity Compensation Plans

The following table provides information as of December 31, 2005 with respect to compensation plans (including individual compensation arrangements) under which our equity securities are authorized for issuance.

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Item 6. Selected Financial Data

The selected financial data presented below for each of the years in the five-year period ended December 31, 2005 is derived from our audited consolidated financial statements. You should read the selected financial data presented below in conjunction with our consolidated financial statements, the notes to our consolidated financial statements and Item 7 “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

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Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The following discussion of our financial condition and results of operations should be read together with the consolidated financial statements and the notes to those statements included elsewhere in this document. This discussion contains forward-looking statements that involve risks and uncertainties. This discussion addresses only our continuing operations, except in the discussion under the heading, “Discontinued Operations.” For more information on our discontinued operations, please see Note 16 to our consolidated financial statements.

Overview

We are a leading provider of innovative technologies and solutions for mission-critical national security programs for the Intelligence Community, the Departments of Defense, State, Homeland Security, and Justice, and other U.S. federal government agencies. Our expertise includes engineering, systems integration, software services, enterprise architecture, information assurance and security architecture, intelligence operations and analysis support, network and critical infrastructure protection, information operations and computer forensics, information technology, communications integration and engineering support. With approximately 6,000 highly qualified employees, we operate in the United States and over 40 countries worldwide.

We derive revenue primarily from contracts with U.S. government agencies that are focused on national security and as a result, funding for our programs is generally linked to trends in U.S. government spending in the areas of defense, intelligence and homeland security. Leading up to and following the terrorist events of September 11, 2001, the U.S. government substantially increased its overall defense, intelligence and homeland security budgets. In 2005, our revenue increased mainly as a result of the expansion of our work with intelligence agencies in U.S.; efforts involving telecommunications, infrastructure, maintenance, repair and sustainment support provided in military deployed environments with U.S. and allied forces in support of peace-keeping efforts worldwide; support to the State Department; and the acquisitions that occurred in the past two years, including Gray Hawk Systems, Inc. in May 2005, and two operations from ACS in 2004.

For the three years ended December 31, 2005, over 90% of our revenues were derived from our customers in the Intelligence Community and the Department of Defense. These customers include the Office of the Secretary of Defense, the Department of State, the Department of Homeland Security, various intelligence agencies, joint intelligence task forces, the U.S. Army, Navy, Air Force and Marine Corps and joint military commands. We also provide solutions to federal government civilian agencies, including the Department of Justice, NASA, and EPA, as well as to state and local governments and commercial customers. The following table shows our revenue from each type of customer as a percentage of our total revenue for the period shown.

Our services and solutions are provided under three types of contracts: time and materials; cost reimbursable; and fixed price. Our contract mix varies from year to year due to numerous factors including our business strategies and federal government procurement objectives. The following table shows our revenue from each of these types of contracts as a percentage of our total revenue for the periods shown.

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Time and materials contracts. Under time and materials contracts, we are reimbursed for labor at fixed hourly rates and generally reimbursed separately for allowable materials, costs and expenses. To the extent that our actual labor costs under a time and materials contract are higher or lower than the billing rates under the contract, our profit under the contract may be either greater or less than we anticipated or we may suffer a loss under the contract. We recognize revenues under time and materials contracts by multiplying the number of direct labor hours expended by the contract billing rates and adding the effect of other billable direct costs. In general, we realize a higher profit margin on work performed under time and materials contracts than cost reimbursable contracts.

Cost reimbursable contracts. Under cost reimbursable contracts, we are reimbursed for costs that are determined to be reasonable, allowable and allocable to the contract, and paid a fee representing the profit margin negotiated between us and the contracting agency, which may be fixed or performance based. Under cost reimbursable contracts we recognize revenues and an estimate of applicable fees earned as costs are incurred. We consider fixed fees under cost reimbursable contracts to be earned in proportion to the allowable costs incurred in performance of the contract. For performance based fees under cost reimbursable contracts, we recognize the relevant portion of the expected fee to be awarded by the client at the time such fee can be reasonably estimated, based on factors such as our prior award experience and communications with the client regarding performance. For cost reimbursable contracts with performance-based fee incentives that are subject to the provisions of U.S. Securities and Exchange Commission Staff Accounting Bulletin No. 104, Revenue Recognition (SAB104), we recognize the relevant portion of the fee upon customer approval. In general, cost reimbursable contracts are the least profitable of our government contracts.

Fixed price contracts. Under fixed price contracts, we perform specific tasks for a fixed price. Compared to cost reimbursable and time and materials contracts, fixed price contracts generally offer higher profit margin opportunities but involve greater financial risk because we bear the impact of cost overruns in return for the full benefit of any cost savings. We generally do not undertake complex, high-risk work, such as long-term software development, under fixed price terms. Fixed price contracts may include either a product delivery or specific service performance over a defined period. Revenue on fixed price contracts that provide for the Company to render services throughout a period is recognized as earned according to contract terms as the service is provided on a proportionate performance basis. These contracts are generally less than six months in duration. For fixed price contracts that provide for the delivery of a specific product with related customer acceptance provisions, revenues are recognized as those products are delivered and accepted.

We have derived a substantial majority of our revenues from governmental contracts under which we act as a prime contractor. We also provide services indirectly as a subcontractor. The following table shows our revenues as prime contractor and as subcontractor as a percentage of our total revenue for the following periods:

Revenue

Substantially all of our revenue is derived from services and solutions provided to the federal government, primarily by our employees and, to a lesser extent, our subcontractors. In some cases, our revenue includes third-party hardware and software that we purchase and integrate as a part of our overall solutions. The level of hardware and software purchases we make for clients may vary from period to period depending on specific contract and client requirements. Since we earn higher profits from labor services that our employees provide compared with subcontracted efforts and other reimbursable items such as hardware and software purchases for clients, we seek to optimize our labor services on all of our engagements.

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Operating Expenses

Cost of Services

Cost of services primarily includes direct costs incurred to provide our services and solutions to customers. The most significant portion of these costs are direct labor costs, including salaries and wages, plus associated fringe benefits, of our employees directly serving customers, in addition to the related management, facilities and infrastructure costs. Cost of services also includes other direct costs such as the costs of subcontractors and outside consultants, and third-party materials, such as hardware or software that we purchase and provide to the customer as part of an integrated solution. Since we earn higher profits on our own labor services, we expect the ratio of cost of services as a percent of revenue to decline when our labor services mix increases relative to subcontracted labor or third-party material. Conversely, as subcontracted labor or third-party material purchases for customers increase relative to our own labor services, we expect the ratio of cost of services as a percent of revenue to increase. Changes in the mix of services and equipment provided under our contracts can result in variability in our contract margins.

General and Administrative Expenses

General and administrative expenses include the salaries and wages, plus associated fringe benefits including stock-based compensation, of our employees not performing work directly for clients. Among the functions covered by these costs are facilities, corporate business development, bid and proposal, contracts administration, finance and accounting, legal, corporate governance, and executive and senior management.

Depreciation and Amortization

Depreciation and amortization includes the depreciation of computers, furniture and other equipment, the amortization of third party software we use internally, leasehold improvements and intangible assets. Identifiable intangible assets are amortized over their estimated useful lives. Non-compete agreements are generally amortized straight-line over the term of the agreement, while contracts and related client relationships are amortized proportionately against the acquired backlog.

Interest Expense

Interest expense is primarily related to interest expense incurred or accrued under our outstanding borrowings and notes payable and, to a lesser extent, our interest rate swap agreement, deferred financing charges and interest on capital leases.

Provision for Income Taxes

We estimate our effective income tax rate to be approximately 39.2%, 38.0% and 40.6% for the years ended 2005, 2004 and 2003, respectively.

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Results of Operations

The following table sets forth the relative percentages that certain items of expense and earnings bear to revenue.

Consolidated Statements of Operations

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Year Ended December 31, 2005 Compared to Year Ended December 31, 2004

Revenues

Revenues increased 18.5% to $980.3 million for the year ended December 31, 2005, compared to $826.9 million for the same period in 2004. This increase is partially attributable to forward deployment support in Iraq and Afghanistan and increased work in the Intelligence Community. Revenue increased approximately $65.2 million from our customer U.S. Army Lifecycle Management Command (LCMC-HQ) (formerly Communications-Electronic Command Headquarters—CECOM-HQ) which accounted for 19.7% and 15.4% of our revenues for the years ended December 31, 2005 and 2004, respectively. Also contributing to the increase was a full year of revenues from certain operations we acquired from Affiliated Computer Services, Inc. (ACS) on February 27, 2004 and June 1, 2004. Approximately $52.9 million of the increase in revenues is attributable to our acquisition of Gray Hawk on May 31, 2005.

Cost of services

Cost of services increased 19.0% to $805.9 million for the year ended December 31, 2005, compared to $677.2 million for the same period in 2004. This increase was largely attributable to the corresponding increases in revenues. As a percentage of revenues, cost of services increased from 81.9% to 82.2%, or 0.3% of revenues. For the year ended December 31, 2005, other direct costs increased by 23.1% over 2004, from $274.6 million to $338.1 million. This increase was attributable to an increase in pass-through costs in 2005 over 2004, a full year of results from costs incurred on contracts purchased from ACS as well as the addition of Gray Hawk in the second quarter of 2005. As a percentage of revenues, other direct costs increased to 34.5% for year ended December 31, 2005 from 33.2% for the same period in 2004. Direct labor costs increased by 16.2% primarily due to an increase in employee headcount as a result of the addition of Gray Hawk and the continued growth of our business. As a percentage of revenue, direct labor costs decreased 1.0% to 47.7% for the year ended December 31, 2005 compared to 48.7% for the same period in 2004.

Gross profit

Gross profit increased 16.5% to $174.4 million for the year ended December 31, 2005, compared to $149.7 million for the same period in 2004. The increase in gross profit can be attributed to the growth of our business through recent acquisitions as well as expansion with our existing contract base. Gross profit margin decreased to 17.8% for the year ended December 31, 2005, compared to 18.1% for the same period in 2004. The decrease in gross profit margin is due to a less profitable mix of direct labor and other direct costs including subcontractors and material purchases partially offset by a reduction, as a percentage of revenue, in direct labor and overhead costs.

General and administrative

General and administrative expenses increased 9.0% to $82.9 million for the year ended December 31, 2005, compared to $76.0 million for the same period in 2004, which is less then the growth of revenue for the same period. The increased expenses reflect additional management personnel and infrastructure, increased bid and proposal efforts, and expenses related to our acquisitions to support the continued growth of our business. As a percentage of revenues, general and administrative expenses decreased to 8.5% for the year ended December 31, 2005 from 9.2% for the same period in 2004.

Depreciation and amortization

Depreciation and amortization expense increased 38.8% to $7.2 million for the year ended December 31, 2005, compared to $5.2 million for the same period in 2004. A majority of the increase resulted from additional amortization of intangibles from the Gray Hawk acquisition of $1.0 million.

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Income from continuing operations

Income from continuing operations increased 23.2% to $84.4 million for the year ended December 31, 2005, compared with $68.5 million for the same period in 2004. Operating margin increased to 8.6% for the year ended December 31, 2005 from 8.3% for the same period in 2004. The increase in margin is primarily due to reduced general and administrative expense, as a percentage of revenues.

Interest expense, net

Interest expense, net increased 17.9% to $2.3 million for the year ended December 31, 2005, compared with $1.9 million for the same period in 2004. The increase in interest expense is a result of increased borrowing under our credit facility in the second quarter of 2005 to finance our acquisition of Gray Hawk and higher interest rates.

Gain on disposal of operations

On February 11, 2005, we sold our ManTech Environmental Technology, Inc (“METI”) subsidiary to Alion Science and Technology Corporation. The sale generated a pre-tax gain of $3.7 million in 2005. In December 2005, we sold our 40 percent interest in Vosper-ManTech joint venture in the United Kingdom of Great Britain, which resulted in a $1.6 million pre-tax gain. For additional information see “Gain on Disposal of Operations,” below.

Loss from discontinued operations

In February 2005, we reached the determination to sell our MSM subsidiary after we concluded that the MSM business no longer furthered our long-term strategic objectives. Currently, we intend to sell MSM as a going-concern and are in discussions with potential buyers. We expect to complete the sale or other disposition of the MSM operations by the end of the second quarter of 2006. At December 31, 2005, we recorded a loss accrual of $ 3.6 million on the valuation of these assets based on offers received from potential buyers in early 2006. The loss accrual reflects the write-off of intangible assets including goodwill, net of taxes. The loss also reflects a valuation allowance of $1.3 million for deferred state income tax assets related to net operating losses carried forward, which are not expected to be realized. Net losses from MSM were $8.8 million and $17.2 million for 2005 and 2004, respectively. In 2003, MSM had net income of $3.6 million. For additional information see “Discontinued Operations,” below.

Net income

Net income increased 78.9% to $44.2 million for the year ended December 31, 2005, compared to $24.7 million for the same period in 2004. The increase is a result of higher revenue, increased income from continuing operations, a reduced loss on discontinued operations of $9.0 million in 2005 versus a loss of $17.2 million for the same period in 2004, a $1.8 million after-tax gain on the sale of METI and $1.0 million after-tax gain on the sale of our interest in our Vosper-ManTech joint venture. Discontinued operations for the period ended December 31, 2004 contained an after-tax adjustment for a change in estimate for revenue earned of $13.2 million plus a pre-tax estimated contract loss of $4.7 million on our Defense Security Services contract. The results from discontinued operations are primarily due to our MSM subsidiary that was categorized as discontinued during the first quarter of 2005, as discussed in “Discontinued Operations” below. Our effective tax rate for years ended December 31, 2005 and 2004 was 39.2% and 38.0%, respectively.

Year Ended December 31, 2004 Compared to the Year Ended December 31, 2003

Revenues

Revenues increased 23.9% to $826.9 million for the year ended December 31, 2004, compared to $667.2 million for 2003. This increase is largely attributable to several factors, including: $27.5 million in revenue from the acquisition of operations from ACS in the first and second quarters of 2004; a full-year versus ten months of

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revenue ($10.3 million) from Integrated Data Systems (IDS), which was acquired in early 2003; $31.4 million in revenue as a result of our expansion of the logistical readiness, telecommunications, infrastructure, maintenance, repair and sustainment support provided in military deployed environments with U.S. and allied forces in support of peace-keeping efforts worldwide; $23.8 million in revenue from additional work under contracts that were in existence during the prior year; $11.2 million in revenue as a result of operations related to information technology forensics and intrusion; and $10.0 million in revenue from our contract to support relocation of a U.S. Army Special Operations Command Center. The total increase attributable to the factors described above is $114.2 million. The remaining amount of increase, $45.5 million, is due to increased work from Department of Defense and various intelligence agencies.

Cost of services

Cost of services increased 24.2% to $677.2 million for the year ended December 31, 2004, compared to $545.5 million for 2003. As a percentage of revenues, cost of services increased from 81.8% to 81.9%. Out of the $131.7 million increase in cost of services, over $23.9 million is attributable to cost incurred on operations purchased from ACS during the first and second quarters of 2004.

Direct labor costs, including fringe benefit costs and applicable overhead, increased from $331.8 million to $402.6 million, or 21.4%, due to an increase in personnel, increased salaries and increased benefit costs. For the year ended December 31, 2004, other direct costs increased from $213.7 million to $274.6 million, or 28.5%, over the year ended December 31, 2003. Direct labor costs increased by 20.7% due to an increase in personnel, primarily related to our acquisitions, direct new hires and increased salaries. As a percentage of revenues, other direct costs increased to 33.2% for the year ended December 31, 2004, from 32.0% for the same period in 2003, due to increased pass-through sales.

For the year ended December 31, 2004, other direct costs increased by 28.5% over the twelve months of 2003, from $213.7 million to $274.6 million. This increase was attributable to an increase in pass-through costs in 2004 over 2003, year-to-date results from IDS, and costs incurred on contracts purchased from ACS.

Gross profit

Gross profit increased 23.0% to $149.7 million for the year ended December 31, 2004, compared to $121.8 million for the same period in 2003. The gross profit of our operations remained relatively constant, at 18.1% to 18.2% for the years ended December 31, 2004 and 2003, respectively.

General and administrative

General and administrative expenses increased 21.4% to $76.0 million for the year ended December 31, 2004, compared to $62.6 million for 2003 as a result of additional management personnel and infrastructure to support the growth of our business. In addition, we recorded $0.8 million in costs related to terminating a lease agreement for an idle facility and $0.3 million in costs related to close one of the offices located in the Washington D.C. area. As a percentage of revenues, general and administrative expenses remained relatively constant at 9.2% and 9.4% for the years ended December 31, 2004 and December 31, 2003, respectively.

Depreciation and amortization

Depreciation and amortization expense increased 19.2% to $5.2 million for the year ended December 31, 2004, compared to $4.4 million in 2003. The increase resulted primarily from an additional $0.3 million of amortization of intangible assets established in connection with our recent acquisitions and an additional $0.5 million of depreciation expense from additional fixed assets placed in operation as a result of our operational growth.

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Income from continuing operations

Income from continuing operations increased 25.0% to $68.5 million for the year ended December 31, 2004, compared with $54.8 million for 2003. This increase is aligned with the increase in revenue generated from our operations.

Loss from discontinued operations

Loss from discontinued operations was $17.2 million for the period ended December 31, 2004 verses income of $3.6 million for 2003. Discontinued operations for the period ended December 31, 2004 contained a pre-tax adjustment for a change in estimate for revenue earned of $13.2 million plus a pre-tax estimated contract loss of $4.7 million on our Defense Security Services contract. The results from discontinued operations are primarily due to our MSM subsidiary, as discussed in “Discontinued Operations” below.

Net income

Net income decreased 29.7% to $24.7 million for the year ended December 31, 2004, compared to $35.2 million for 2003, mainly as a result of losses from our discontinued MSM operations. Net income excluding MSM increased 32.7% to $41.9 million for the year ended December 31, 2004 from $31.6 million for the year ended December 31, 2003. Our effective tax rate for year ended December 31, 2004 and 2003 was 38.0% and 40.6%, respectively.

Backlog

For the years ended 2005, 2004 and 2003 our backlog was $2.3 billion, $1.6 billion, and $1.4 billion respectively, of which $467 million, $444 million, and $357 million, respectively, was funded backlog. Backlog and funded backlog represent estimates that we calculate on a consistent basis. The 2005 acquisition of Gray Hawk Systems Inc. contributed approximately $233 million to backlog for the year ended 2005. Several significant contract wins, including a competitive award to support the U.S. Army in Iraq and Afghanistan and several significant classified awards occurring in 2005 bolstered our Backlog at December 2005 We estimate that approximately 35% to 45% of our total backlog will be recognized as revenues prior to December 31, 2006.

Effects of Inflation

We generally have been able to price our contracts in a manner to accommodate the rates of inflation experienced in recent years. Under our time and materials contracts, labor rates are usually adjusted annually by predetermined escalation factors. Our cost reimbursable contracts automatically adjust for changes in cost. Under our fixed-price contracts, we include a predetermined escalation factor, but generally, we have not been adversely affected by inflation.

Liquidity and Capital Resources

Our primary liquidity needs are the financing of working capital, capital expenditures and acquisitions. Our primary source of liquidity is cash provided by operations and our $125.0 million revolving credit facility. As of December 31, 2005, we had an outstanding balance of $42.4 million under our credit facility. At December 31, 2005, we were contingently liable under letters of credit totaling $3.5 million, which reduces our ability to borrow under our credit facility. The maximum available borrowing under our credit facility at December 31, 2005 was $79.1 million. Generally, cash provided by operating activities is adequate to fund our operations. Due to fluctuations in our cash flows and the growth in our operations, it is necessary from time to time to increase borrowings under our credit facility to meet cash demands. In the future, we may borrow greater amounts in order to finance acquisitions or new contract start ups. In 2005, we increased our borrowing by $17.4 million, net of repayments, to fund our acquisition of Gray Hawk Systems, Inc.

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Cash flows from operating activities

Our operating cash flow is primarily affected by the overall profitability of our contracts, our ability to invoice and collect from our clients in a timely manner, and our ability to manage our vendor payments. We bill most of our clients and prime contractors monthly after services are rendered. The increase in 2005 over the previous year is primarily related to final dividends from our investment in our Vosper-ManTech joint venture of $3.0 million and a net cash inflow from discontinued operations of $14.2 million. In 2004, discontinued operations used cash of $12.0 million. The positive cash flow in discontinued operations for 2005 is due to the collection of all outstanding receivables on our Defense Security Services contract. In 2003, cash provided by operating activities was generated primarily from net income of $35.2 million and increases in accounts payable and accruals, offset by an increase in contract receivables and an increase in prepaid items.

Cash flows from investing activities

Our cash flow used in investing activities consists primarily of capital expenditures and business acquisitions offset by disposals of operations. Investing activities in 2005 included the acquisition of Gray Hawk Systems for $101.2 million, net of cash acquired, and a $5.6 million final earn out payment related to the IDS acquisition offset by the disposal of METI for $7.0 million and sale of our 40% interest in the Vosper-ManTech joint venture for $1.7 million. Purchases of property, equipment and software totaled $7.1 million which included $2.0 million purchase of office buildings and land. Cash used in investing activities during 2004 included purchases of property, equipment and software of $6.2 million, acquisition of certain assets of ACS and earn out payments on prior year’s acquisitions. Cash used in investing activities was $74.2 million for the year ended December 31, 2003. Investing activities for 2003 included the acquisitions of IDS and MSM, which used $63.7 million and $5.1 million, respectively. In the future, we expect to continue with selective acquisitions that are consistent with our strategic plan for growth.

Cash flows from financing activities

Our cash flow provided by financing activities consists primarily of proceeds from exercise of stock options and net change on our credit facility. Cash provided from financing in 2005 was the result of stock option exercises of $9.5 million and a net increase in borrowings against our credit facility to finance our acquisition of Gray Hawk Systems in May 2005. The net cash provided by financing activities in 2004 was a result of proceeds from the exercise of stock options. The net cash provided by financing activities during 2003 was the result of $2.1 million in proceeds received from employees upon the exercise of stock options, less our $1.0 million payment of the final installment of not-to-compete financings.

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Credit Agreement

On February 25, 2004, we executed an Amended and Restated Credit and Security Agreement with Citizens Bank of Pennsylvania, KeyBank National Association, Branch Banking and Trust Company of Virginia, Chevy Chase Bank, F.S.B., and Riggs Bank, N.A., in order to increase the capacity available under our prior loan agreement. The agreement initially provides for a $125 million revolving credit facility that can be increased to $200 million. The maturity date of the agreement is February 25, 2009. Our credit facility contains covenants that limit or restrict our ability to borrow additional money, merge or consolidate, sell or dispose of assets other than in the ordinary course of business, make acquisitions, enter into related-party transactions, pay dividends, and make certain capital expenditures. Our credit facility also requires us to maintain specified financial covenants relating to asset coverage, fixed charge coverage, and debt coverage ratios. Borrowings under the agreement are collateralized by our assets and bear interest at the London Inter-Bank Offer Rate (LIBOR), or the lender’s base rate, plus market-rate spreads that are determined based on a company leverage ratio calculation. To manage our exposure to the fluctuations in these variable interest rates, we executed an interest swap in December 2001. The swap agreement had a notional principal amount of $25.0 million and a fixed LIBOR rate of 6.83%. In December 2005, our swap agreement terminated. As of December 31, 2005, we were in compliance with all material covenants under the Credit Agreement.

We believe the capital resources available to us under our credit agreements and cash from our operations are adequate to fund our ongoing operations and to support the internal growth we expect to achieve for at least the next 12 months. We anticipate financing our external growth from acquisitions and our longer-term internal growth through one or more of the following sources: cash from operations; additional borrowing; issuance of equity; use of the existing revolving facility; or a refinancing of our credit facilities.

Off-Balance Sheet Arrangements

Effective June 20, 2003, our lenders issued two letters of credit to Fianzas Guardiana Inbursa, S.A. (FGI) on behalf of GSE Systems, Inc. (GSE). As discussed in note 12 to our consolidated financial statements, prior to the sale of these investments on October 21, 2003, we held common and preferred stock in GSE and accounted for this investment using the equity method.

The first letter of credit, which was cancelled in March 2005, was in support of an advance payment bond of approximately $1.8 million, issued by FGI to a customer of GSE’s power business and had a term of 30 months. The second letter of credit is in support of a performance bond of approximately $1.3 million issued by FGI to the same customer and has a term that expires on June 20, 2006. The letter of credit can be drawn upon by FGI in the event that the related bond is drawn on by the customer, which would only occur in the event of a contractual default by GSE. In the event that the letter of credit is drawn upon, we and GSE have signed a collateral agreement whereby GSE has agreed to indemnify us from any and all costs, damages, claims, actions, demands, losses and expenses (including the value of the letter of credit drawn upon, reasonable attorneys’ fees, collection fees or enforcement fees). In exchange for issuing the letters of credit, we received 100,000 warrants to purchase GSE’s common stock at the market price of GSE’s common stock as of the close of business on July 8, 2003, and will receive a 7% annual fee, payable on a quarterly basis, calculated on the total amount of the then-existing value of the letters of credit.

During 2005, George J. Pedersen, our Chairman of the Board and Chief Executive Officer, beneficially owned shares and options of GSE stock representing less than 5% of GSE. In 2005, Mr. Pedersen served on GSE’s board of directors and compensation committee.

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Contractual Obligations

The following table is in thousands.

Gain on Disposal of Operations

On February 11, 2005, we sold our METI subsidiary to another company, Alion Science and Technology Corporation. METI performs research and development in the fields of environmental and life sciences for the Environmental Protection Agency, the National Cancer Institute, the U.S. Air Force, and other federal government agencies. The financial terms of the arrangement included an all cash payment of $7 million, which resulted in a pre-tax gain of approximately $3.7 million net of selling cost in 2005. Although we have sold METI, we continue to provide professional services in the environmental area for various federal government agencies.

In December 2005, we sold our 40 percent interest in our Vosper-ManTech joint venture in the United Kingdom to Vosper Thornycroft Limited for approximately $4.3 million including accrued dividends. The sale resulted in a $1.6 million pre-tax gain recorded in gain on disposal of operations.

Discontinued Operations

Our Consolidated Financial Statements and related note disclosures reflect our ManTech MSM Security Services, Inc. (MSM) subsidiary as “Long-Lived Assets to Be Disposed of by Sale” for all periods presented in accordance with Statement of Financial Accounting Standards No. 144—Accounting for the Impairment or Disposal of Long-Lived Assets. As such, MSM is classified as held for sale in the consolidated balance sheets and discontinued operations, net of applicable income taxes in the consolidated statements of income.

In February 2005, we reached the final corporate determination that we would exit the personnel security investigation (PSI) services business and discontinue operations at our MSM subsidiary. We reached the determination to sell our MSM subsidiary after we concluded that the MSM business no longer furthered our long-term strategic objectives. Currently, we intend to sell MSM as a going-concern and are in discussions with potential buyers. We expect to complete the sale or other disposition of the MSM operations by the end of the second quarter of 2006. As noted above, we recorded a loss accrual for $3.6 million at December 31, 2005 based on offers received from potential buyers in early 2006. The loss accrual reflects the write-off of intangible assets including goodwill, net of taxes. The loss also reflects a valuation allowance of $1.3 million for deferred state income tax assets related to net operating losses carried forward, which are not expected to be realized.

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Critical Accounting Estimates and Policies

Critical accounting policies are defined as those that are reflective of significant judgments and uncertainties, and potentially result in materially different results under different assumptions and conditions. Application of these policies is particularly important to the portrayal of our financial condition and results of operations. The discussion and analysis of our financial condition and results of operations are based on our consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States of America. The preparation of these consolidated financial statements requires management to make estimates and judgments that affect the reported amount of assets, liabilities, revenues and expenses. Actual results may differ from these estimates under different assumptions or conditions. Our significant accounting policies, including the critical policies listed below, are more fully described in the notes to the consolidated financial statements included in this report.

Revenue Recognition and Cost Estimation

We recognize revenue when persuasive evidence of an arrangement exists, services have been rendered, the contract price is fixed or determinable, and collectibility is reasonably assured. We have a standard internal process that we use to determine whether all required criteria for revenue recognition have been met.

Our revenues consist primarily of services provided by our employees, and to a lesser extent, the pass through of costs for materials and subcontract efforts under contracts with our customers. Cost of services consists primarily of compensation expenses for program personnel, the fringe benefits associated with this compensation, and other direct expenses incurred to complete programs, including cost of materials and subcontract efforts.

We derive the majority of our revenue from cost-plus-fixed-fee, cost-plus-award-fee, firm-fixed-price, or time-and-materials contracts. Revenues for cost-reimbursement contracts are recorded as reimbursable costs are incurred, including an estimated share of the applicable contractual fees earned. For performance-based fees under cost reimbursable contracts, that are subject to the provisions of Statement of Position 81-1, Accounting for Performance of Construction-Type and Certain Production-Type Contracts (SOP 81-1), we recognize the relevant portion of the expected fee to be awarded by the client at the time such fee can be reasonably estimated, based on factors such as our prior award experience and communications with the client regarding performance. For cost reimbursable contracts with performance-based fee incentives that are subject to the provisions of U.S. Securities and Exchange Commission Staff Accounting Bulletin No. 104, Revenue Recognition (SAB104), we recognize the relevant portion of the fee upon customer approval. For time-and-material contracts, revenue is recognized to the extent of billable rates times hours delivered plus material and other reimbursable costs incurred. For long-term fixed-price production contracts, revenue is recognized at a rate per unit as the units are delivered, or by other methods to measure services provided. Revenue from other long-term fixed-price contracts is recognized ratably over the contract period or by other appropriate methods to measure services provided. Contract costs are expensed as incurred except for certain limited long-term contracts noted below. For long-term contracts which are specifically described in the scope section of American Institute of Certified Public Accountants (“AICPA”) Statement of Position (“SOP”) No. 81-1, “Accounting for Performance of Construction Type and Certain Production-Type Contracts,” or other appropriate accounting literature we apply the percentage of completion method. Under the percentage of completion method, income is recognized at a consistent profit margin over the period of performance based on estimated profit margins at completion of the contract. This method of accounting requires estimating the total revenues and total contract cost at completion of the contract. During the performance of long-term contracts, these estimates are periodically reviewed and revisions are made as required. The impact on revenue and contract profit as a result of these revisions is included in the periods in which the revisions are made. This method can result in the deferral of costs or the deferral of profit on these contracts. Because we assume the risk of performing a fixed-price contract at a set price, the failure to accurately estimate ultimate costs or to control costs during performance of the work could result, and in some instances has resulted, in reduced profits or losses for such contracts. Estimated losses on contracts at completion are recognized when identified. In certain circumstances, revenues are recognized when contract amendments have not been finalized.

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Goodwill

Goodwill represents the excess of cost over the fair value of net tangible and identifiable intangible assets of acquired companies. Effective January 1, 2002, we adopted SFAS No. 142, and no longer amortize goodwill; rather, we review goodwill at least annually for impairment. We have elected to perform this review annually during the second quarter of each calendar year and no adjustments were necessary. For acquisitions completed prior to the adoption of SFAS No. 141 and SFAS No. 142 on January 1, 2002, goodwill was amortized on a straight-line basis over periods ranging from two to twenty years.

As noted above in our discussion of “Discontinued Operations” above, we recorded at December 31, 2005 a loss accrual for the impairment of goodwill related to MSM.

Recent Accounting Pronouncements

In December 2004, the Financial Accounting Standards Board (FASB) issued SFAS No. 123 (revised 2004), “Share-Based Payment,” which will require the compensation costs related to share-based payment transactions to be recognized in financial statements. With limited exceptions, the amount of compensation will be measured based on the grant-date fair value of the equity instruments issued. Compensation cost will be recognized over the vesting period during which an employee provides service in exchange for the award. SFAS No. 123(R) is effective January 1, 2006 for the company. We will adopt the modified prospective method for reporting utilizing the Black-Scholes model for valuing our stock-based compensation on date of grant.

Information about the fair value of stock options under the Black-Scholes model and its pro forma impact on the Company’s net earnings and earnings per share for the historical periods is illustrated in Note 2 of our financial statements under Stock-based Compensation disclosure. We expect the impact of implementing the new standard will be a reduction in diluted earnings per share of approximately $0.10 to $0.12 for the fiscal year ending December 31, 2006. The new pronouncement will also require excess tax benefits related to the exercise of stock options be reported in the statement of cash flows as an inflow from financing activities and an outflow from operating activities. As of December 31, 2005, all of our grants under the 2002 plan had a 10 year contractual life. For future grants, we intend to shorten the contractual life to 5 years. At December 31, 2005, we had approximately $9.2 million of unrecognized compensation expense for awards outstanding to be amortized ratably over the remaining service period less an estimate for forfeitures.

Item 7A. Quantitative and Qualitative Disclosures about Market Risk

Our exposure to market risk relates to changes in interest rates for borrowings under our revolving credit facility. These borrowings bear interest at variable rates. A hypothetical 10% increase in interest rates would have increased our annual interest expense for the year ended December 31, 2005 by less than $0.4 million.

In December 2001, we entered into an interest swap agreement in order to reduce our exposure associated with the market volatility of fixed LIBOR interest rates. This agreement had a notional principal amount of $25.0 million and, as of December 31, 2004, had a rate of 6.83%. This agreement was a hedge against revolving debt of $25.0 million, which contained interest at monthly floating LIBOR plus a margin currently at 1.00%. At stated monthly intervals the difference between the interest on the floating LIBOR-based debt and the interest calculated in the swap agreement was settled in cash. This agreement expired in December 2005. We have no other interest rate swap outstanding at December 31, 2005.

We do not use derivative financial instruments for speculative or trading purposes. We invest our excess cash in short-term, investment grade, interest-bearing securities. Our investments are made in accordance with an investment policy approved by the board of directors. Under this policy, no investment securities can have maturities exceeding one year and the average maturity of the portfolio cannot exceed 90 days.

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Item 8. Financial Statements and Supplementary Data

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

ON THE CONSOLIDATED FINANCIAL STATEMENTS

To the Board of Directors and Stockholders of ManTech International Corporation

Fairfax, Virginia

We have audited the accompanying consolidated balance sheets of ManTech International Corporation and subsidiaries (the “Company”) as of December 31, 2005 and 2004, and the related consolidated statements of income, changes in stockholders’ equity and cash flows for each of the three years in the period ended December 31, 2005. Our audits also included the financial statement schedule listed at Item 15(a)(2). These financial statements and financial statement schedule are the responsibility of the Company’s management. Our responsibility is to express an opinion on these financial statements and financial statement schedule based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, such consolidated financial statements present fairly, in all material respects, the financial position of ManTech International Corporation and subsidiaries as of December 31, 2005 and 2004, and the results of their operations and their cash flows for each of the three years in the period ended December 31, 2005, in conformity with accounting principles generally accepted in the United States of America. Also, in our opinion, the financial statement schedule, when considered in relation to the basic consolidated financial statements taken as a whole, presents fairly in all material respects the information set forth herein.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the effectiveness of the Company’s internal control over financial reporting as of December 31, 2005, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated March 8, 2006 expressed an unqualified opinion on management’s assessment of the effectiveness of the Company’s internal control over financial reporting and an unqualified opinion on the effectiveness of the Company’s internal control over financial reporting.

/s/ DELOITTE & TOUCHE LLP

McLean, Virginia

March 8, 2006

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MANTECH INTERNATIONAL CORPORATION

CONSOLIDATED BALANCE SHEETS

(Dollars in Thousands)

See notes to consolidated financial statements.

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MANTECH INTERNATIONAL CORPORATION

CONSOLIDATED BALANCE SHEETS (Continued)

(Dollars in Thousands)