Black and Veatch, Overland Park, Kansas (HDTRA118D0003); Raytheon Co., Dulles, Virginia (HDTRA118D0004); URS Federal Services, Cleveland, Ohio (HDTRA118D0005); Parsons Government Services International Inc., Pasadena, California (HDTRA118D0006); CH2M Hill Inc., Herndon, Virginia (HDTRA118D0007), and PAE National Security Solutions LLC, Fredericksburg, Virginia (HDTRA118D0008), are each being awarded a modification to each respective indefinite-delivery/indefinite-quantity, multiple award services contract for the Cooperative Threat Reduction (CTR) Program. The mission of the CTR Program is to partner with willing countries to reduce threat from weapons of mass destruction and related materials, technologies, facilities, and expertise. The modification increases the maximum dollar ceiling, including the base period and seven options for all six contracts combined, by $164,400,000, from $970,000,000 to $1,134,400,000. Work will be performed at various locations throughout the world. Task Orders issued under the contract may be for a duration of three years past the last ordering date of the contracts. Funding will be obligated for each task order and no funds are obligated on the basic contracts. The Defense Threat Reduction Agency, Fort Belvoir, Virginia, is the contracting activity.