To amend title 10 to shorten breach reporting timelines, increase program transparency, and improve congressional oversight of Department of Defense cost overruns with respect to the cost growth for major systems, and for other purposes.

H.R. 4372 seeks to tighten and accelerate the Nunn-McCurdy breach reporting process, increase transparency, and strengthen congressional oversight of Department of Defense (DoD) cost overruns on major defense systems. Key changes include requiring breach notifications and related determinations to be reported to Congress within 30 days, creating a new mechanism to designate individual end items as major subprograms for reporting when multiple end items carry large life-cycle costs, and requiring life-cycle operations and support costs to be included in reporting. The bill also enhances public disclosure of cost-growth certifications, imposes additional termination options and timelines if cost growth persists, and limits the ability of the Secretary to delegate certain certification duties. Overall, the bill aims to improve transparency and accountability around large, high-risk defense programs and to provide more explicit, timely options for terminating or restructuring programs that experience repeated cost growth.