The Thrift Savings Plan is the largest defined contribution plan in the United States, covering 7.2 million federal civilian employees and uniformed service members with $963 billion in assets as of December 2024. It is also one of the few defined contribution plans in the country that actually requires spousal consent before a participant can remove funds. A March 2026 GAO report examining spousal protections across the retirement system offers a detailed look at how the TSP’s consent framework works — including its notable gap on beneficiary designations.