H.R. 4159 requires the Secretary of Defense to establish regulations ensuring that optional combat boots worn by military personnel must be entirely made in America—including all materials and components—within 730 days of the law's enactment. The bill applies to all branches of the armed forces and covers boots that service members choose to wear as part of their required uniform, but not those issued directly by the Defense Department. The legislation includes two exemptions: the military can waive the requirement for boots designed for specific operational needs if American-made alternatives aren't available, and service members who need special boots for medical reasons are exempt from the requirement. This bill aims to support domestic manufacturing while balancing military readiness and individual health needs.