# Missile Defense Agency The **Missile Defense Agency (MDA)** is the Defense Department component responsible for developing and fielding integrated ballistic-missile defense — the institutional descendant of the Strategic Defense Initiative Organization created under Reagan, renamed and restructured into its current form in 2002. For this vault, MDA matters chiefly as the pre-existing home for a mission that [[Golden Dome]] has been built partly outside of. When a flagship program is stood up with its own leadership and a funding path that runs through reconciliation rather than the agency's regular budget, the question of what MDA still owns is an oversight question, not an org-chart one. > [!note] Stub — fill out > To expand: SDIO lineage, the GMD and Aegis BMD programs, the test record, budget history, and the division of labor with [[Golden Dome]] and [[U.S. Space Force]]. ## See Also - [[Golden Dome]] — the current flagship program - [[Strategic Defense Initiative]] — the Reagan-era ancestor - [[U.S. Space Force]] · [[Department of Defense]]