The Thrift Savings Plan (TSP) is a defined contribution plan for United States civil service employees and retirees as well as for members of the uniformed services. As of December 31, 2020, TSP has approximately 6.2 million participants (of which approximately 3.8 million are actively participating through payroll deductions), and more than $735.2 billion in assets under management; it is the largest defined contribution plan in the world. The TSP is administered by the Federal Retirement Thrift Investment Board, an independent agency.