From the Document: "The Ground Based Strategic Deterrent (GBSD)--recently designated the LGM-35A Sentinel missile--is expected to replace the Minuteman III (MMIII) Intercontinental Ballistic Missile (ICBM) in the U.S. nuclear force structure. MMIII has served as the ground-based leg of the U.S. nuclear triad--land-based ballistic missiles, submarine-launched ballistic missiles, and nuclear-capable bombers-- since 1970. (For details, see CRS Report RL33640, U.S. Strategic Nuclear Forces: Background, Developments, and Issues, by Amy F. Woolf.) The Air Force expects the Sentinel (GBSD) to begin replacing MMIII in 2029. Although some in Congress and outside government have debated whether to continue the program, the Biden Administration has included $3.6 billion for the GBSD program in its FY2023 budget request and is expected to endorse the program in its Nuclear Posture Review." The updated CRS Report RL33640 can be found here: [https://www.hsdl.org/?abstract&did=862361].
CRS In Focus, IF11681
Congressional Research Service: https://crsreports.congress.gov/