General Dynamics Electric Boat Corp., Groton, Connecticut, is awarded a $122,781,126 cost-plus fixed-fee modification to previously awarded contract N00024-20-C-2120 for lead yard support and development studies and design efforts related to Virginia-class submarines. This contract modification includes options which, if exercised, would bring the cumulative value of the modification to $164,071,626. Work will be performed in the continental U.S. and is expected to be completed by August 2025. Fiscal 2022 research, development, test, and evaluation funding in the amount of $10,000,000 will be obligated at time of award and will expire at the end of the current fiscal year. This contract was not competitively procured. The statutory authority for this sole source award is in accordance with Defense Federal Acquisition Regulation 6.302-1(a)(2)(iii) — only one responsible source and no other supplies or services will satisfy agency requirements. The Naval Sea Systems Command, Washington, D.C., is the contracting activity.