[Excerpt] The Thrift Savings Plan plays a pivotal role in helping federal workers achieve adequate retirement income. Employees enrolled in the FERS who do not make voluntary contributions to the TSP, and thus receive only the 1% agency automatic contribution, will be able to replace only 1% to 3% of final annual salary from the TSP at retirement. Most workers in the lower and middle ranges of the federal salary scale will be able to achieve the 70% salary replacement recommended by many pension analysts from the benefits paid by Social Security and the FERS basic retirement annuity, but this is not so for higher-wage federal workers. Federal employees at all income levels can significantly boost their retirement income by contributing to the TSP, and such contributions are essential in order for those in the upper third of the federal pay scale to achieve a level of income that will allow them to maintain their pre-retirement standard of living.