Thrift Savings PlanThe G Fund is the Thrift Savings Plan’s government securities fund. It holds short-term U.S. Treasury securities issued specially to the TSP, its principal and interest are backed by the U.S. government, and it is the only TSP fund that has never lost money in a calendar year.
That guarantee is why federal employees and service members treat it as their safe money — and why so many hold far more of it than their timeline calls for.
No market risk to your principal, no negative year in twenty, and the lowest long-run return of the five core funds at 2.85% a year. The G Fund protects the dollars you have; it does not grow them fast. Its real risk is inflation, not loss.
What the G Fund actually holds
Unlike the other four funds, the G Fund does not track a public index and you cannot buy its holdings anywhere else. It is invested in nonmarketable short-term U.S. Treasury securities issued specifically to the TSP. Because the securities are not traded on an open market, the fund’s share price does not fall when interest rates rise — the interest rate resets, but the principal does not swing. That single structural detail is what makes the G Fund different from every ordinary bond fund, including the TSP’s own F Fund.
What the G Fund costs
TSP administrative expenses are among the lowest of any retirement plan in the country, and the TSP publishes a net expense ratio for every fund each year. We do not print a figure here, because our data source covers returns rather than the fee schedule and we only publish numbers we can point to — check the current published net expense ratio for the G Fund on tsp.gov. What matters for a decision is the ranking: TSP costs are low enough that they are almost never the reason to choose one of these funds over another. Choose on risk and role instead.
Risk profile: the safest fund, and the slowest
Over 2006–2025 the G Fund returned between 0.97% and 4.93% in every single year. There is no drawdown to report, because there was never a losing year to recover from. In 2008 it returned +3.75% while the I Fund lost 42.43%; in 2022, when both stocks and bonds fell, it returned +2.98% and was the only one of the five core funds in positive territory.
The cost of that steadiness is compounding. At 2.85% a year, $10,000 became $17,552 over the twenty years. In the C Fund the same $10,000 became $80,821.11. Over a thirty-year career, holding too much G Fund is its own kind of loss — it just never shows up on a statement as a minus sign.
G Fund annual returns, 2006–2025
| Year | G Fund return |
|---|---|
| 2006 | 4.93% |
| 2007 | 4.87% |
| 2008 | 3.75% |
| 2009 | 2.97% |
| 2010 | 2.81% |
| 2011 | 2.45% |
| 2012 | 1.47% |
| 2013 | 1.89% |
| 2014 | 2.31% |
| 2015 | 2.04% |
| 2016 | 1.82% |
| 2017 | 2.33% |
| 2018 | 2.91% |
| 2019 | 2.24% |
| 2020 | 0.97% |
| 2021 | 1.38% |
| 2022 | 2.98% |
| 2023 | 4.22% |
| 2024 | 4.40% |
| 2025 | 4.44% |
Calendar-year returns for the G Fund, January 2006 through December 2025. Click a column heading to sort — sorting by return is the fastest way to see the best and worst years. Source: Portfolio Visualizer export used for the Retirement Edge TSP backtest.
The G Fund has no negative year in this period, so its “worst year” is simply its lowest positive one.
2008, 2020 and 2022 — the G Fund in the three stress tests
2008: +3.75%. The year that made the G Fund’s reputation. While the C Fund lost 36.99% and the S Fund 38.32%, G Fund holders finished the year ahead.
2020: +0.97%. Its weakest year of the twenty. It gave up nothing in the March crash, but it also gave up the rebound — the S Fund finished 2020 up 31.85%.
2022: +2.98%. The most useful year in the record. Stocks fell and the F Fund fell 12.83% with them; only the G Fund held its ground. If your plan assumes bonds will cushion a stock decline, 2022 says the G Fund is the part of the TSP that actually did.
Who the G Fund suits — and who it does not
It suits you if you are within a few years of retirement or already drawing from your TSP, you have money earmarked for a near-term need, or you need a place to stand during a decline without leaving the plan.
It does not suit you if you are decades from retirement and using it as your default. A 100% G Fund allocation at 35 is not a conservative choice — it is a decision to let inflation set your standard of living in retirement.
The other TSP funds
- C FundLarge-cap U.S. stocks · 11.01%
- S FundSmall and mid-cap U.S. stocks · 9.53%
- I FundInternational stocks · 5.91%
- F FundU.S. investment-grade bonds · 3.41%
- All five, side by sideThe TSP funds hub
The part a table cannot tell you
How much of the G Fund to hold, and when that should change, is the actual question. Our TSP allocation by age guide gives a decade-by-decade framework, you can pressure-test any mix in the TSP Calculator, and the TSP Edge model portfolio is a rules-based monthly update built from these same five funds — research you choose to act on, with most months saying nothing needs to change.