But development difficulties delayed progress and drove up costs. Ultimately, the program produced 21 B-2s at an average cost of $2.13 billion each (~$4.17 billion in 2024), including development, engineering, testing, production, and procurement.

Boeing developed the GBU-57, and as of 2015, the aerospace company had been contracted to produce 20 of them, according to the Air Force. Because of the GBU-57's weight — it's the heaviest bomb produced by the U.S. — the B-2 Spirit is currently the only aircraft in the Air Force that is equipped to carry and deploy it.

The United States's B-2 stealth bomber is currently the only aircraft designed to deploy the GBU-57 bunker buster bombs.