When investing in the TSP, be sure to make sure you balance both risk and reward. You also should be sure to take into account the risk and reward potential of any other investments you have.

The TSP directly offers the following funds:

  • Government Securities Investment Fund (G Fund), special Treasury issues with an average maturity date of about 14 years;
  • Common Stock Index Fund (C Fund), which tracks the Standard & Poor’s 500 index of large U.S. stocks;
  • Fixed Income Index Investment Fund (F Fund), a combination of corporate and government bonds;
  • Small Capitalization Index Investment Fund (S Fund) tracking the Wilshire 4500;
  • International Stock Index Investment Fund (I Fund), tracking the Barclays EAFE index; and
  • Lifecycle Funds (L Funds), in which investors pick from one of the available target withdrawal dates (2025-2065 in five-year increments) or an “income fund” for those already withdrawing their accounts or close to that point.

Note: During 2024, the TSP is transitioning the I fund to a broader index of international stocks, reflecting stock markets of more countries, and stocks of smaller companies in addition to mid-sized and large companies.

L fund money is allocated among the other TSP funds according to a pre-set formula balancing potential risk and return, with ever-increasing proportions in the stock-based funds as the time frame lengthens and with automatic adjustments on a daily basis to keep the desired ratios.

Until late 2018, the target-date funds also adjusted their investment mixes each calendar quarter to slightly reduce their stock-fund holdings, making them more conservative as the projected withdrawal date approached. However, the TSP at that time froze the overall stock vs. non-stock fund allocations in each of the L funds. It will keep those ratios frozen until the mixes match what they would have been had they started with a more aggressive profile; within those two broad categories, slight changes in allotments among individual funds are continuing.

It also made the income fund more aggressive with increases in the share of stocks phased in over 10 years.

Mutual Fund Window—The TSP in 2022 began offering an investment “window” through which account holders can invest part of their money in outside mutual funds. There are a number of restrictions, however, including that such investments must be made by transferring money already in an existing TSP account; they cannot be made through ongoing payroll withholding. Also, there is a minimum $10,000 initial outside investment; a ban on making new outside investments that would bring the share of TSP’s own funds in the total account to less than 75 percent; and annual and per-transaction fees.