ManTech to Hold Groundbreaking Ceremony in Aberdeen, Md.

ManTech International Corporation (NASDAQ:MANT) (www.mantech.com), a leading provider of technical and engineering services and solutions vital to the nation's interest and security, will hold a groundbreaking ceremony at the construction site of its new location at Water’s Edge Corporate Campus in Aberdeen, Md. As the site’s first tenant, ManTech will occupy 63,000 square feet of the building’s 125,000-square-foot space, starting in March 2011. The project is led by construction company Manekin LLC, in conjunction with Alex Brown Realty, Inc.

Scheduled attendees and speakers at the ceremony include: Honorable C.A. "Dutch” Ruppersberger, U.S. House of Representatives, Maryland’s 2^nd District; John McDonough, Secretary of State, State of Maryland; David R. Craig, Harford County Executive; James C. Richardson, Director, Harford County Office of Economic Development; J. Thomas Sadowski, President and CEO, Economic Alliance of Greater Baltimore; George J. Pedersen, Chairman of the Board and CEO of ManTech International Corporation; Lawrence B. Prior III, President and COO, ManTech; and Richard Alter, President and CEO, Manekin.

About ManTech International Corporation

Headquartered in Fairfax, Va., with approximately 9,000 professionals, 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; 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.