Thrift Savings PlanThe Thrift Savings Plan is refreshingly simple: five core funds and a set of Lifecycle funds. That simplicity is a strength — but only if you know what each fund actually holds and what job it does.
This page is the map. Each fund gets a short description and its twenty-year record here, with a link to a full guide covering what it holds, what it costs, how it behaves in a crash, and who it suits.
The C, S and I funds are your growth engines (stocks). The F and G funds are your stability (bonds and government securities). The L funds bundle all five into an automatic, age-based mix. Everything else is just how you weight them.
The five core funds at a glance
- C FundLarge-cap U.S. stocks · 11.01% a year
- S FundSmall and mid-cap U.S. stocks · 9.53%
- I FundInternational stocks · 5.91%
- F FundU.S. investment-grade bonds · 3.41%
- G FundGovernment securities · 2.85%
- All five, year by yearFull 20-year performance data
The three stock funds — your growth engine
- C Fund — tracks the S&P 500, the 500 largest U.S. companies. The workhorse of most portfolios and the best-compounding core fund of the last twenty years. Full C Fund guide →
- S Fund — small and mid-sized U.S. companies outside the S&P 500. A bumpier ride, and over 2006–2025 a lower return than the C Fund. Full S Fund guide →
- I Fund — international stocks. It diversifies you away from betting everything on one country’s economy, at the cost of the lowest long-run return of the three. Full I Fund guide →
These three are where long-term growth comes from. When retirement is decades away, they should do most of the heavy lifting.
The two stability funds — your ballast
- F Fund — a broad U.S. investment-grade bond index. Modest returns, a counterweight when stocks fall in a growth scare — but it lost 12.83% in 2022. Full F Fund guide →
- G Fund — government securities issued specially to the TSP. It has never posted a negative calendar year. This is your true ballast. Full G Fund guide →
The five funds compared, 2006–2025
| Fund | What it holds | 20-yr annualized | Best year | Worst year |
|---|---|---|---|---|
| C Fund | Large-cap U.S. stocks | 11.01% | 32.45% (2013) | -36.99% (2008) |
| S Fund | Small / mid-cap U.S. stocks | 9.53% | 38.35% (2013) | -38.32% (2008) |
| L 2030 | All five, age-based mix | 7.33% | 22.50% (2009) | -27.51% (2008) |
| I Fund | International stocks | 5.91% | 32.45% (2025) | -42.43% (2008) |
| F Fund | Investment-grade U.S. bonds | 3.41% | 8.68% (2019) | -12.83% (2022) |
| G Fund | Government securities | 2.85% | 4.93% (2006) | 0.97% (2020) |
January 2006 – December 2025, sourced from Portfolio Visualizer. The G Fund has no negative year in this period, so its “worst year” is its lowest positive one. Year-by-year figures for all five funds are on the TSP fund performance page.
See how any combination of the five funds actually projects over time:
The L (Lifecycle) funds — all five, on autopilot
The L funds (L 2030, L 2040, and so on) hold all five core funds in a single package and automatically shift from stocks toward the G and F funds as your target date approaches. They are the hands-off option. We cover exactly how they glide — and what that convenience can cost — in our guide to the L funds.
Which funds should you actually use?
Knowing what each fund holds is step one. Step two is deciding how much to put in each — and that depends heavily on how far you are from retirement. Our best TSP allocation by age guide walks through a decade-by-decade framework, and you can pressure-test any mix in the TSP Calculator.
The part that actually matters: discipline
A sound allocation only helps if you hold it through the uncomfortable moments and adjust it for the right reasons. That is the idea behind the TSP Edge strategy — a rules-based monthly update that tells you when a change is warranted, so your TSP follows evidence instead of emotion. Most months, it says do nothing, which is usually the hardest and most correct answer.