Current TSP G Fund interest rate

As of May 2025, the TSP G Fund interest rate is 4.250%. The rate is calculated monthly, based on the average yield of all U.S. Treasury securities with 4 or more years to maturity. The chart and table below show the recent history of the G Fund rate.

Historical interest rates for the G Fund

The G Fund interest rate is currently 4.250%. But it returned over 9 percent per year shortly after it was launched in the late 1980s:

The G Fund compares very favorably to other risk-free investments. In the charts above and below you can see that the interest rate on the G Fund is almost always higher than the 3-month Treasury Bill yield. There are some exceptions though — notice how the G Fund interest rate was lower than that on Treasury Bills during the inflation spike in 2023-2024:

Overall, the TSP G Fund has held up well against inflation.

G Fund Returns

The TSP G Fund will not lose money — its returns are guaranteed by the U.S. Government. That makes it very different from a typical bond fund, where your principal fluctuates with the rise and fall of interest rates. The chart below shows the historical performance of the TSP G Fund, and is updated every business day with the latest TSP G Fund price:

The G Fund has earned a compound annualized return of 4.7% since its launch in April 1987. Its year-to-date return is 1.7%, and its 1-year return is 4.4%. A $1,000 investment in 1987 would be worth $5,734 today.