ManTech Awarded Information Technology Support Services (ITSS-4) Contract to Provide Support Services to Department of Justice

ManTech International Corporation (NASDAQ:MANT) (www.mantech.com), a leading provider of innovative technologies and solutions for mission-critical national security programs, today announced the company was awarded a prime contract with the U.S. Department of Justice to provide information technology support services to the Department of Justice (DOJ) and all DOJ offices, boards, divisions and bureaus. The multiple-award, indefinite-delivery/indefinite-quantity (IDIQ) contract has a base period of March 9, 2011 through September 30, 2011 and six option years, with a total ceiling value of $1.1 billion for all awardees.

Under the Information Technology Support Services (ITSS-4) contract, ManTech will support a wide range of lifecycle IT-related tasks and processes, including systems development, IT planning, systems engineering, systems development and testing, systems programming and integration, systems conversions, interoperability verification and testing, cyber security, technology infusion, continuity of operations and other technology services for all DOJ components.

The ITSS-4 contract will enable the DOJ to connect to resources to support the IT infrastructure critical to the success of the agency’s mission, including cyber defense, intelligence and counterintelligence, law enforcement, administration, incarceration, grants management, and criminal and civil litigation. It also will help the DOJ meet the needs of its widely dispersed workforce.

"ManTech is a longstanding partner to the U.S. Department of Justice, supporting key mission areas including intelligence, cyber security, secure networking, IT sustainment operations and other security services,” said L. William Varner, president and chief operating officer of ManTech’s Mission, Cyber and Technology Solutions group. "We look forward to continuing our support of the DOJ in its endeavors to enforce the law and defend the interests of the United States.”

About ManTech International Corporation

Headquartered in Fairfax, Va., with more than 10,000 professionals in 40 countries around the world, 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, including the Federal Bureau of Investigation; the space community; the National Oceanic and Atmospheric Administration; and other U.S. federal government customers. ManTech's expertise includes systems engineering, systems integration, enterprise architecture, cyber security, information assurance, intelligence operations and analysis support, network and critical infrastructure protection, information operations and information warfare support, information technology, communications integration, global logistics and supply chain management, and service-oriented architectures. 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. These forward-looking statements are inherently subject to risks and uncertainties, and actual results and outcomes may differ materially from the results and outcomes we anticipate. Factors that could cause actual results to differ materially from the results we anticipate, include, but are not limited to, the following: failure to obtain option awards, task orders or funding under contracts; risk of contract performance, modification or termination; adverse changes in future levels of expenditures for programs we support caused by budgetary pressures facing the federal government; and risks associated with complex U.S. government procurement laws and regulations. These and other risk factors are more fully discussed in the section entitled "Risks Factors” in ManTech’s Annual Report on Form 10-K previously filed with the Securities and Exchange Commission on Feb. 25, 2011, and in ManTech’s other filings with the Securities and Exchange Commission. The forward-looking statements included in this news release are only made as of the date of this press 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.