The Thrift Savings Plan (TSP) is a retirement savings and investment plan for Federal employees and members of the uniformed services, including the Ready Reserve., The Thrift Savings Plan (TSP) is a retirement savings and investment plan for Federal employees and members of the uniformed services, including the Ready Reserve., The Thrift Savings Plan (TSP) is a retirement savings and investment plan for federal government employees and uniformed services members, including the Ready Reserve., The Thrift Savings Plan (TSP) is a retirement savings and investment plan for Federal employees and members of the uniformed services, including the Ready Reserve., The Thrift Savings Plan (TSP) is a retirement savings and investment plan for Federal employees and members of the uniformed services, including the Ready Reserve., The Thrift Savings Plan (TSP) is a retirement savings and investment plan for Federal employees and members of the uniformed services, including the Ready Reserve..