The Thrift Savings Plan is the federal government's version of a 401(k) — and under the Blended Retirement System, it's one of the most underused benefits in military pay. Every service member who enlisted since January 1, 2018 gets free money deposited into a TSP account whether they ever think about it or not. Most just don't know how to make it work harder.

How TSP Contributions Work Under BRS

From the day you enter service under BRS, the government automatically contributes 1% of your base pay to your TSP — you don't have to contribute anything to get this. After 2 years of service, the government also starts matching your own contributions dollar-for-dollar on the first 3%, then 50 cents on the dollar for the next 2%.

  • 0% contributed by you: You still get 1% from the government — free money, no action required.
  • 3% contributed by you: Government adds 1% automatic + 3% match = 4%. Total: 7%.
  • 5% contributed by you: Government adds 1% automatic + full match (3% + 1%) = 5%. Total: 10% of base pay every pay period.

The rule of thumb: Contribute at least 5% of base pay. Above 5%, the government stops matching — you're just contributing to yourself at that point, which is still worth doing once other financial priorities (emergency fund, high-interest debt) are handled.

Traditional vs. Roth TSP

You can split contributions between two tax treatments:

Traditional TSPRoth TSP
ContributionsPre-tax (reduces taxable income now)After-tax (no deduction now)
Withdrawals in retirementTaxed as ordinary incomeTax-free (including all growth)
Best forHigher tax brackets, or combining with tax-free combat payJunior enlisted, lower current tax bracket

For most E-1 through E-5s, Roth is the better default — you're likely paying little to no federal income tax already, so there's minimal benefit to the Traditional deduction today, and decades of tax-free growth is worth far more than a small deduction now. Note: the government's automatic and matching contributions always go into the Traditional side, regardless of which you choose for your own contributions — you can't avoid that.

The Five Core Funds

FundWhat it holds
G FundGovernment securities — no risk of loss, low return
F FundU.S. bond market index
C FundS&P 500 index (large U.S. companies)
S FundSmall/mid-cap U.S. companies (everything outside the S&P 500)
I FundInternational developed-market stocks

Lifecycle (L) Funds: The Set-and-Forget Option

If picking your own mix of the five core funds sounds like a chore, the Lifecycle Funds do it for you. Pick the L Fund closest to the year you expect to need the money (e.g., L 2050 for someone planning to retire around then), and it automatically blends the core funds — stock-heavy while retirement is decades away, shifting toward bonds as that date approaches. It's the default recommendation for anyone who doesn't want to manage their own allocation, and it's what most financial advisors point junior service members toward first.

What Happens If You Separate Early

Once the 2-year vesting period passes, everything in your TSP — your contributions, the government's automatic and matching contributions, and all investment growth — belongs to you permanently. Separate at 4 years, 10 years, or 20, it doesn't matter: the account follows you out. Leave it in TSP (still some of the lowest fees available), roll it into an IRA for more fund choices, or roll it into a new employer's 401(k). Just don't cash it out — an early withdrawal before age 59½ typically triggers income tax plus a 10% penalty on the taxable portion.

Recommended Reading

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Must Read

The Military Money Manual

Spencer Reese

Covers TSP investing, BRS vs Legacy, VA loans, and building wealth at every rank in one comprehensive guide.

View on Amazon → TSP Investing

The Little Book of Common Sense Investing

John C. Bogle

The foundational case for low-cost index investing — the exact philosophy behind the TSP's C, S, and I Funds.

View on Amazon → BRS Guide

Blended Retirement System Guide

Various Authors

A focused deep-dive on BRS matching mechanics and how to maximize TSP contributions at every pay grade.

View on Amazon →

Frequently Asked Questions

How much should I contribute to TSP to get the full match?
Under BRS, contribute at least 5% of your base pay. The government automatically adds 1% regardless of your own contribution, then matches your first 4% dollar-for-dollar — meaning 5% from you plus 5% from the government equals 10% total going into your TSP every pay period.
Is TSP better than a civilian 401(k)?
In most ways, yes. TSP has some of the lowest expense ratios of any retirement account in the country, and under BRS it comes with automatic and matching government contributions from day one. The main tradeoff is fewer fund choices — five core funds and Lifecycle funds, versus the dozens a typical 401(k) offers.
Should I choose Traditional or Roth TSP?
Roth TSP is usually the better default for junior enlisted, since you're likely in a low tax bracket now and withdrawals in retirement are tax-free. Traditional TSP makes more sense once you're in a higher bracket, since the deduction is worth more today. Many service members split contributions between both.
What happens to my TSP if I separate before 20 years?
It's yours to keep. Once the 2-year matching contributions vest, the account belongs to you regardless of how long you serve. You can leave it in TSP, roll it into an IRA, or roll it into a new employer's 401(k) — but you should not cash it out early, which triggers taxes and a 10% penalty.
What is the Lifecycle (L) Fund?
The L Funds are pre-built target-date portfolios that automatically mix the five core TSP funds based on a chosen retirement year, shifting from stock-heavy to bond-heavy as that date approaches. They're the default, hands-off option most financial advisors recommend.