General Dynamics Electric Boat Corp., Groton, Connecticut, is awarded a $482,115,887 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. Work will be performed in Groton, Connecticut (96%); Newport News, Virginia (3%); and Newport and Quonset, Rhode Island (1%), and is expected to be completed by October 2022. Fiscal 2020 shipbuilding and conversion (Navy) funds in the amount of $53,151,801 (51%); fiscal 2021 shipbuilding and conversion (Navy) funds in the amount of $28,616,832 (27%); fiscal 2016 shipbuilding and conversion (Navy) funds in the amount of $9,094,582 (9%); fiscal 2019 shipbuilding and conversion (Navy) funds in the amount of $6,390,454 (6%); fiscal 2018 shipbuilding and conversion (Navy) funds in the amount of $4,724,999 (4%); and fiscal 2021 research, development, test, and evaluation (Navy) funds in the amount of $3,165,077 (3%) will be obligated at time of award, of which $3,165,077 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 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.