The Aegis ballistic missile defense (BMD) program, which is carried out by the Missile Defense Agency (MDA) and the Navy, gives Navy Aegis cruisers and destroyers a capability for conducting BMD operations. BMD-capable Aegis ships operate in European waters to defend Europe from potential ballistic missile attacks from countries such as Iran, and in in the Western Pacific and the Persian Gulf to provide regional defense against potential ballistic missile attacks from countries such as North Korea and Iran. The number of BMD-capable Aegis ships has been growing over time. MDA’s FY2023 budget submission states that “by the end of FY 2023 there will be 50 total BMDS [BMD Systems] capable [Aegis] ships requiring maintenance support.”

The Aegis BMD program is funded mostly through MDA’s budget. The Navy’s budget provides additional funding for BMD-related efforts. MDA’s proposed FY2023 budget requests a total of $1,659.1 million (i.e., about $1.7 billion) in procurement and research and development funding for Aegis BMD efforts, including funding for two Aegis Ashore sites in Poland and Romania. MDA’s budget also includes operations and maintenance (O&M) and military construction (MilCon) funding for the Aegis BMD program.

Issues for Congress regarding the Aegis BMD program include the following:

• whether to approve, reject, or modify MDA’s annual procurement and research and development funding requests for the program;
• the adequacy of MDA’s cost estimating and its reporting of costs;
• what role the Aegis BMD program should play in defending the U.S. homeland against attack from ICBMs;
• required versus available numbers of BMD-capable Aegis ships;
• the burden that BMD operations may be placing on the Navy’s fleet of Aegis ships, and whether there are alternative ways to perform BMD missions now performed by U.S. Navy Aegis ships, such as establishing additional Aegis Ashore sites;