Roth TSP vs Traditional TSP: Which Is Better?
The Thrift Savings Plan lets you split contributions between Roth (post-tax) and Traditional (pre-tax) accounts. Both invest in the same low-cost TSP funds. The difference is when you pay tax — now or in retirement. For most servicemembers, one of the two is meaningfully better than the other, and it usually comes down to your current tax bracket vs your expected retirement bracket.
The core mechanic
- Traditional TSP: contributions come out of your paycheck before tax. Your taxable income goes down now. When you withdraw in retirement, the entire withdrawal (contributions + growth) is taxed as ordinary income.
- Roth TSP: contributions come out of your paycheck after tax. You pay tax on the money now. When you withdraw in retirement (age 59½+ and account open 5+ years), the withdrawal is completely tax-free — contributions AND growth.
Both options use identical fund choices (G, F, C, S, I, and L funds) and identical contribution limits. The only difference is the tax timing.
The simple rule
Choose Roth TSP if you expect to be in a HIGHER tax bracket in retirement than you are now. Choose Traditional TSP if you expect to be in a LOWER tax bracket in retirement than you are now. If it’s a wash, split contributions between the two.
For most junior enlisted servicemembers, Roth wins. Here’s why: E-1 through E-5 pay lands in the 10–12% federal bracket, sometimes lower after standard deduction. Paying 10–12% tax on your Roth contribution now is likely cheaper than the tax you’d pay pulling that money out in retirement when you might have a military pension + VA disability + civilian income all stacked up.
For senior enlisted and officers (E-7+ / O-4+), the math shifts. If you’re in the 22–24% bracket now, Traditional TSP gives you a bigger tax break today than you’d likely pay in retirement (assuming you retire and drop into lower brackets).
The Roth TSP + tax-free combat pay advantage
Servicemembers deployed to a Combat Zone Tax Exclusion (CZTE) area receive tax-free base pay. Traditional TSP contributions from CZTE pay STILL show up as pre-tax on your account (the “double dip” that used to exist — contributions were tax-free going in AND tax-free growing).
Under current rules, Roth TSP contributions from CZTE pay are the clearest winner: the money goes in tax-free (because it was CZTE pay to begin with), and it comes out tax-free in retirement. Zero tax on that money, forever. If you’re deployed to a CZTE area, max out Roth TSP contributions — this is a unique advantage available only to servicemembers.
Contribution limits
The IRS elective deferral limit applies to your combined Roth + Traditional TSP contributions. If the annual limit is $23,000 (check the current IRS number — it increases most years), you can put any split between the two: $23,000 all Roth, $23,000 all Traditional, or any mix that adds to $23,000. You cannot exceed the total.
DoD matching contributions are ALWAYS Traditional (pre-tax) regardless of where you put your own contributions. So even if you contribute 100% Roth, you’ll have a small Traditional balance from the DoD match. That’s normal and unavoidable.
The 5-year rule for Roth withdrawals
Roth TSP withdrawals of growth are tax-free if two conditions are met:
- You’re age 59½ or older
- Your Roth TSP account has been open for at least 5 tax years
The 5-year clock starts on January 1 of the tax year of your first Roth contribution. If you make your first Roth TSP contribution in 2026, the clock starts January 1, 2026 — you can pull tax-free growth starting January 1, 2031 (assuming you’re 59½ by then).
Contributions can always be withdrawn tax-free (you already paid tax on them). Only growth is subject to the 5-year rule.
Beyond the simple rule: real-world factors
Retirement income stacking
A 20-year military retiree with a pension, VA disability, and possibly a civilian second career can easily exceed their active-duty income in retirement. If you’re on that trajectory, Roth wins — the future you will be in a higher bracket than the current you.
State tax
Some states don’t tax retirement income at all (Florida, Texas, Nevada, Tennessee, Washington, Wyoming, South Dakota, Alaska). Others fully tax it (California, New York). If you plan to retire to a no-tax state, Traditional TSP looks better (no state tax on the withdrawal). If you’ll retire to a high-tax state, Roth looks better (you’d rather have paid tax at a possibly lower state rate now).
Required Minimum Distributions (RMDs)
Traditional TSP is subject to Required Minimum Distributions starting at age 73 (as of current rules; the age has increased over time). You’ll be forced to pull money out and pay tax on it whether you need the income or not. Roth TSP has NO RMD, so you can leave the money growing tax-free indefinitely — a real advantage for estate planning.
Tax rate uncertainty
Federal tax rates could rise between now and your retirement. If you believe rates are going up, Roth is a hedge — pay tax at today’s known rate rather than tomorrow’s unknown higher rate.
How to split if you’re unsure
A common recommendation: 50/50 split for the first several years of your career until you have clarity on your career trajectory. This hedges against being wrong about your future tax bracket. Once you have 5+ years of service and a clearer sense of whether you’re staying in, adjust the split.
The bottom line
For most junior enlisted, Roth TSP is the better default — low current tax bracket + likely higher retirement bracket + the 5-year clock starts as early as possible. For senior enlisted and officers in higher current brackets, Traditional TSP often wins the pure math. When in doubt, split 50/50 and revisit. The one guaranteed mistake is not contributing enough to get the DoD match — that decision matters more than the Roth vs Traditional question.
Veteran Money Guide is educational and is not legal, tax, or financial advice. Every situation is different — verify current rules with the VA, DFAS, IRS, or a qualified professional before making a decision.
