TSP offers five individual investment funds — G Fund (government bonds), F Fund (bond index), C Fund (S&P 500 equivalent), S Fund (small-cap stocks), and I Fund (international stocks) — plus Lifecycle (L) Funds that automatically blend all five based on a target retirement year. New BRS enrollees are defaulted into an age-appropriate L Fund, which is a reasonable starting point. The allocation decision matters significantly: the same contribution amount in different funds can produce six-figure differences in balance over a 20-35 year military career.
What each fund does
G Fund holds short-term U.S. Treasury securities. It cannot lose value from one month to the next — the government guarantees that. The tradeoff is historically modest returns that have sometimes barely kept pace with inflation. Many older accounts default to G Fund if the member never changed settings.
C Fund tracks the S&P 500 — 500 of the largest U.S. companies. Among the individual TSP funds, the C Fund has historically delivered strong long-term returns, with meaningful volatility along the way. Younger investors with decades until retirement often choose higher stock exposure, but the right mix depends on risk tolerance, time horizon, and whether they can stay invested during downturns.
S Fund covers smaller U.S. companies (small-cap stocks). More volatile than C Fund; historically higher returns over some very long periods.
I Fund tracks an international stock index, providing exposure to markets outside the United States. Geographic diversification.
F Fund tracks the U.S. investment-grade bond market. Less volatile than stock funds, lower expected long-term return.
What are Lifecycle (L) Funds?
L Funds blend all five individual funds and automatically shift from aggressive (more stocks) to conservative (more bonds and G Fund) as the target retirement date approaches. L2065 is the most aggressive; L Income is the most conservative, designed for members already in or near retirement.
The target date is meant to align with when you plan to start withdrawing — roughly your anticipated retirement year. L Funds prevent the common mistake of never touching your allocation and leaving everything in the G Fund by default.
Does fund choice actually make a difference?
Yes — substantially. An E-3 at age 20 who invests $10,000 in G Fund versus C Fund could see a six-figure difference by age 60, based on historical return differences, even before any additional contributions. TSP's expense ratios are among the lowest of any workplace retirement plan — typically under 0.06% — so fund allocation rather than fees is the primary variable.
Changing your fund allocation requires logging into TSP.gov, which is a separate system from myPay. Changing your contribution rate requires myPay.
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Project how different fund allocations and contribution rates affect your TSP balance at retirement.
Open Calculator →For a plain-English breakdown of all five funds in more detail, see TSP Fund Options Explained. For what happens to your balance if you never log in and change anything, see TSP for Beginners: What Happens If You Never Change Your Settings.
Educational information about TSP investment options, not investment advice. Past performance does not guarantee future results. Consult TSP.gov for current fund information and performance data.
