From the Document: "The military retirement system is a government-funded system that provides a defined benefit to all retirees and matching government contributions to the Thrift Savings Plan (TSP) for eligible servicemembers. It has historically been viewed as a significant retention incentive for military personnel. The system includes monthly compensation for qualified active and reserve retirees, disability benefits for those deemed medically unfit to serve, and a survivor annuity program for the eligible survivors of deceased retirees. The amount of compensation depends on years of service (YOS), basic pay at retirement, and annual Cost-of-Living-Adjustments (COLAs)."
CRS In Focus, IF10483
Congressional Research Service: https://crsreports.congress.gov/