Raytheon Co., Dulles, Virginia, is being awarded a $15,521,711 modification to a previously awarded firm-fixed-price, cost-plus-fixed-fee contract (N00189-11-C-Z038) for operation and maintenance services in support of the Navy Fleet Surveillance Support Center Relocatable Over-the-Horizon Radar system. This modification includes an eight-month base period and four one-month options, which if exercised, will bring the total value of the contract to $23,402,200. Work will be performed in Kent, Virginia (20 percent); Chesapeake, Virginia (20 percent); Freemont, Texas (15 percent); Freer, Texas (15 percent); Juana Diaz, Puerto Rico (15 percent); and Vieques, Puerto Rico (15 percent), and will be completed by March 2016. Fiscal 2015 operation and maintenance, Navy in the amount of $15,521,711 will be obligated at the time of award and funds will not expire before the end of the current fiscal year. This contract was a sole source pursuant to the authority set forth in 10 U.S.C. 2304(C)(2). One company was solicited and one offer was received. Naval Supply Systems Command, Fleet Logistics Center Norfolk Contracting Department, Philadelphia, is the contracting activity.