Booz Allen Hamilton Inc., McLean, Virginia (N6523621D4800); CSSI Inc., Washington, D.C. (N6523621D4801); DIGITALiBiz Inc., Rockville, Maryland (N6523621D4802); Serco Inc., Herndon, Virginia (N6523621D4803); and Scientific Research Corp., Atlanta, Georgia (N6523621D4804), are awarded a cumulative $279,803,380 multiple award, indefinite-delivery/indefinite-quantity contract with provisions for cost-plus-fixed-fee and firm-fixed-price task/delivery orders. The contracts are for engineering support services and supplies for the conception, design, development and delivery of integrated systems, networks and supporting infrastructure on a non-emergent basis along with the corresponding engineering, technical, and management support services and equipment for air traffic control, meteorology and oceanography, and aviation command, control, communications, computers, combat systems, intelligence, surveillance, and reconnaissance electronic systems. These contracts include a single five-year ordering period with an estimated cumulative value of $279,803,380. These contracts also include a two-year option ordering period. The option period, if exercised, would bring the cumulative value of these contracts to an estimated $400,000,000. Fiscal 2021 working capital (Navy) funds in the amount of $25,000 ($5,000 per awardee) will be obligated at the time of award. Funds will not expire at the end of the current fiscal year. Work will be performed in Charleston, South Carolina (77%); and San Diego, California (23%). Work is expected to be completed by May 2028. If options are exercised, work could continue until May 2030. The contracts were competitively procured by full and open competition via the Naval Information Warfare Systems Command – Electronic Commerce Central website and the website, with five offers received. Naval Information Warfare Center Atlantic, Charleston, South Carolina, is the contracting activity.