TSP for Military Members

Automatic 1%: DoD deposits 1% of your base pay into your TSP whether you contribute or not. Vests after 2 years of service.
Matching up to 4%: DoD matches your contributions dollar-for-dollar on the first 3%, then 50 cents on the dollar for the next 2%. Total: you contribute 5%, DoD contributes 5% = 10% of your base pay going into TSP.
Critical: The match is calculated monthly. If you max out early in the year, you get no match for the remaining months. Pace your contributions to hit $24,500 in December, not July.

No government matching. You can still contribute to TSP and benefit from the tax advantages and low fees, but there is no free money component. Your retirement income comes primarily from the pension (50% of highest 36 months of base pay at 20 years). TSP is a supplement, not a replacement.

Service members enrolled on or after October 1, 2020 are auto-enrolled at 5% of base pay (previously 3%). Contributions go into the Traditional TSP and are invested in the age-appropriate L (Lifecycle) Fund by default. You can change your contribution percentage, Roth/Traditional split, and fund allocation at any time through myPay.

Military-specific note: Unlike civilian employees who can contribute dollar amounts per paycheck, military members contribute as a percentage of base pay. Calculate your percentage to hit exactly $24,500 in December — not before. If you max out early, the match stops for the remaining months of the year.

Contributions come from pre-tax pay — you don’t pay income tax on the money going in. Your taxable income is lower today. You pay taxes when you withdraw in retirement. Best if you expect to be in a lower tax bracket in retirement than you are now.

Contributions come from after-tax pay — you pay income tax now, but withdrawals in retirement are completely tax-free, including all the growth. Best if you expect to be in a higher tax bracket in retirement, or if you want tax diversification.

Junior enlisted are in the lowest tax brackets of their lives. An E-3 or E-4 with BAH and BAS (both tax-free) often has a federal taxable income under $25,000. Paying 10–12% tax now to lock in tax-free growth and withdrawals for decades is a powerful trade. As your career progresses, your income rises. In retirement, between pension, TSP withdrawals, and Social Security, your tax bracket will likely be higher than it is as an E-4.

Important: The BRS match always goes into your Traditional TSP, regardless of your election. You cannot change this. This means even if you contribute 100% Roth, you’ll still have a Traditional balance from the government match — giving you some built-in tax diversification.

In a combat zone, you can contribute up to the $72,000 annual additions limit (including employer contributions). However, Roth contributions are still capped at $24,500. Any amount above $24,500 must go into Traditional TSP. So the optimal strategy is: contribute $24,500 to Roth (triple tax-free), then put the rest into Traditional up to $72,000.

Even in a combat zone, the same monthly match rule applies. If you max out contributions too early, the match stops. The annual additions limit ($72,000) applies to the entire calendar year, not just your deployment period. Plan your contribution percentage to pace evenly.

The G Fund is the safest fund: it invests in short-term government securities and has never lost money in any period. But that safety comes at a steep cost. Its average annual return is roughly 2–4% — barely keeping pace with inflation. A 25-year-old E-3 who leaves all contributions in the G Fund for 30 years will accumulate dramatically less than one who invests in the C or S Fund. The difference can be hundreds of thousands of dollars.

C Fund (Common Stock Index) — tracks the S&P 500. Large US companies. Historically ~10% avg annual return. This is the workhorse.
S Fund (Small Cap Stock Index) — tracks small and mid-cap US stocks. Higher growth potential, more volatile.
I Fund (International Stock Index) — tracks international developed-market stocks. Adds global diversification.
F Fund (Fixed Income Index) — tracks US investment-grade bonds. Lower risk, lower return than stocks.
G Fund (Government Securities) — US Treasury securities. Lowest risk, lowest return.

L Funds automatically adjust your allocation from aggressive (more C/S/I) to conservative (more G/F) as you approach your target retirement date. If you don’t want to manage your own allocation, an L Fund matched to your expected retirement year is a reasonable hands-off approach. The default for auto-enrolled members is the age-appropriate L Fund.

The younger you are and the further you are from withdrawal, the more you can tolerate short-term volatility in exchange for long-term growth. A 22-year-old with 40+ years until retirement has time to ride out market downturns. A heavy C/S allocation is age-appropriate. As you approach retirement age, gradually shifting toward F and G reduces risk. This is not financial advice — your risk tolerance and goals are personal. But leaving everything in the G Fund at age 22 is almost always the wrong answer.

Often the best option. TSP’s expense ratios (~0.05%) are lower than most civilian 401(k) plans and many IRAs. Your money continues to grow, you retain access to all fund options, and you can change allocations anytime at TSP.gov. You can also roll a civilian employer’s 401(k) into your TSP to take advantage of the low fees.

You can roll your TSP into a Traditional or Roth IRA for potentially more investment options (individual stocks, ETFs, sector funds). Traditional TSP rolls to Traditional IRA; Roth TSP rolls to Roth IRA. Be aware: IRA expense ratios are often higher than TSP, and you lose the unique G Fund (guaranteed return with no market risk).

Before age 59½: Generally subject to a 10% early withdrawal penalty plus income tax (Traditional) or penalty on earnings only (Roth, if not qualified). Exception — Rule of 55: If you separate from federal service (including military) during or after the calendar year you turn 55, you can withdraw from TSP penalty-free. This is earlier than the standard 59½ rule and is a significant advantage for military retirees.

While serving, you can borrow from your TSP (general purpose loan or residential loan). After separation, outstanding loans must be repaid in full or the balance becomes a taxable distribution plus the 10% penalty if under 59½. If you’re planning to separate, consider this carefully.

Cashing out your TSP at separation is the single most destructive financial decision a separating service member can make. You’ll pay income tax on the full amount (Traditional) plus a 10% penalty if under 59½. A $50,000 TSP cashed out at separation could cost you $15,000+ in taxes and penalties — and that $50,000, left invested for 30 years at 7%, would have grown to over $380,000.

Not contributing 5% under BRS. You are giving back free money. Even if you have debt, the instant 100% return on the first 3% (dollar-for-dollar match) beats almost any interest rate you’re paying.

Maxing out too early. If your contributions hit $24,500 in July, you get zero match from August to December. Pace your percentage to reach the limit in the last pay period of the year.

Leaving everything in the G Fund. The G Fund is for capital preservation near retirement, not for a 22-year-old with decades of growth ahead. Check your allocation at TSP.gov.

Contributing Traditional while deployed. Combat zone pay is already tax-free. Putting it into Traditional TSP means you’ll pay taxes when you withdraw. Switch to Roth before deployment to capture the triple tax advantage.

Cashing out at separation. That $30,000 today could be $230,000+ in 30 years. Leave it in TSP, roll it to an IRA, or roll it into a new employer’s 401(k) — but don’t cash it out.