ManTech Awarded $7.1 Million Contract from DHS for United States Public Private Partnership Program.

FAIRFAX, Va. -- ManTech International Corporation (Nasdaq:MANT), a leading provider of innovative technologies and solutions focused on mission-critical national security programs for the Intelligence Community; the Departments of Defense, State, Homeland Security, and Justice; the Space Community; and other U.S. federal government customers, announced today that it has been awarded a contract from the Department of Homeland Security's Operations Directorate for the United States Public Private Partnership (USP3) Engineering and Management Support program. The competitively awarded contract is for one year, and has three option years for a total potential value to ManTech of $7.1 million.

USP3 is an unclassified network that immediately provides the Department's Homeland Security Operations Center with one-stop, 24/7 access to a broad spectrum of industries, agencies and critical infrastructure across both the public and private sectors, including chemical facilities. This conduit for two-way information sharing provides the Department with an expanding base of locally knowledgeable experts and delivers real-time access to critical information. The USP3 initiative was expanded to include critical infrastructure owners and operators and the private sector in all 50 states centered regionally around the cities of Dallas, Seattle, Indianapolis and Atlanta. To date, USP3 communicates with nearly 40,000 members and is expected to grow to 200,000 members.

Under the USP3 program, ManTech will provide a Web-based collaboration and information sharing portal; an emergency resource registration system; a nationwide alert and warning notification system; and the training, operations and maintenance, and program management required to support the system.

"ManTech welcomes the opportunity to further support DHS in its critically important mission of information sharing with its state, local and private sector partners," said Joseph Fox, President of ManTech Information Systems and Technology. "Our experience as the lead integrator for the Homeland Security Information Network will allow us to effectively and rapidly field a robust USP3 capability for DHS."

About ManTech International Corporation:

Headquartered in Fairfax, Virginia, ManTech International Corporation 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; the Space Community; and other U.S. federal government customers. ManTech's expertise includes systems engineering, systems integration, technology and software development, enterprise security architecture, information assurance, intelligence operations support, network and critical infrastructure protection, information technology, communications integration and engineering support. The company supports the advanced telecommunications systems that are used in Operation Iraqi Freedom and in other parts of the world; provides the physical and cyber security to protect U.S. embassies all over the world; has developed a secure, collaborative communications system for the U.S. Department of Homeland Security; and builds and maintains secure databases that track terrorists. With over 6,000 highly qualified employees, the company operates in the United States and over 44 countries worldwide. In 2005, Red Herring magazine selected ManTech as one of its Small Cap 100 Companies. Additional information on ManTech can be found at www.mantech.com.

Forward-Looking Information:

Statements and assumptions made in this press release, which do not address historical facts, constitute "forward-looking" statements that ManTech believes to be within the definition in the Private Securities Litigation Reform Act of 1995 and involve risks and uncertainties, many of which are outside of our control. Such forward-looking statements are subject to factors that could cause actual results to differ materially from anticipated results. The factors that could cause actual results to differ materially from those indicated by such forward-looking statements include but are not limited to: the failure of the government to award task orders to ManTech, allot funds to complete performance of the task orders awarded to ManTech, or exercise contract options; the risk of contract performance; government contract procurement (such as bid protest) and termination risks; competitive factors such as pricing pressures and/or competition to hire and retain employees; and material changes in laws or regulations applicable to the Company's businesses. For a discussion of these and other risks and uncertainties, please refer to the section entitled "Risks Related to the Company's Business" in ManTech's Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 10, 2006, and, from time to time, in ManTech's other filings with the Securities and Exchange Commission, including among others, its reports on Form 10-Q and Form 8-K. The forward-looking statements included in this news release are only made as of the date of this news release and ManTech undertakes no obligation to publicly update any of the forward-looking statements made herein, whether as a result of new information, subsequent events or circumstances, changes in expectations or otherwise.