The following is the Sept. 30, 2019 Congressional Research Service report, Defense Budget and the Budget Control Act: Frequently Asked Questions.
From the report
Enacted on August 2, 2011, the Budget Control Act of 2011 as amended (P.L. 112-25, P.L. 112 240, P.L. 113-67, P.L. 114-74, P.L. 115-123, and P.L. 116-37) sets limits on defense and nondefense discretionary spending. As part of an agreement to increase the statutory limit on public debt, the BCA aimed to reduce annual federal budget...
https://news.usni.org/2019/10/03/u-s-defense-budget-budget-control-act-frequently-asked-questions