TSP Roth In-Plan Conversions 2026: Complete Military Guide

Before January 28, 2026, the only way to move Traditional TSP money into a Roth account was to roll it out of the TSP entirely. You'd transfer to a Traditional IRA, then convert to a Roth IRA. Most active-duty members couldn't do this at all.

That changed. The TSP now lets you convert Traditional balances directly to Roth within the plan. No rollover required. No separation from service. Same low-fee TSP funds.

This matters for every BRS member. Your government matching contributions (up to 5% of base pay) always go to Traditional, even if you contribute to Roth. Year after year, that match builds a taxable balance. Converting those dollars now, while you're in a lower tax bracket than you'll likely be as a retiree collecting pension, Social Security, and TSP withdrawals, locks in a lower rate permanently.

This guide covers the conversion rules, the tax bracket math by rank, and five mistakes that cost military members thousands. If you're planning a combat zone deployment, our TSP Roth + CZTE guide covers that specific strategy in detail.

What Changed January 28, 2026

The SECURE 2.0 Act of 2022 required the TSP to offer Roth in-plan conversions. After three years of implementation work, the feature went live on January 28, 2026. The Federal Register published the final rule on January 15, 2026.

Before this date, your only conversion option was to separate from service (or reach age 59.5), roll your Traditional TSP to a Traditional IRA, and then convert that IRA to Roth. This was slow, complicated, and unavailable to most active-duty members.

Now you can convert any amount from Traditional TSP to Roth TSP with a few clicks on TSP.gov. The money never leaves the TSP. Your fund allocations stay the same. The only thing that changes is the tax treatment: pre-tax dollars become after-tax Roth dollars, and you owe income tax on the converted amount.

How In-Plan Conversions Work

A Roth in-plan conversion moves money from your Traditional TSP balance to your Roth TSP balance. The converted amount becomes taxable income for that year. In exchange, that money (and all future growth on it) is never taxed again.

The TSP does not withhold taxes on conversions. You pay the full tax bill from your own funds when you file your return, or through quarterly estimated payments.

Conversion Rules at a Glance

The BRS Match Problem

If you're under BRS and contribute to Roth TSP, you might think your entire balance is Roth. It isn't.

The government's matching contributions always go to your Traditional TSP balance. Every pay period. Even if 100% of your personal contributions go to Roth. The breakdown:

• 1% automatic contribution: Goes to Traditional
• Dollar-for-dollar match on first 3% you contribute: Goes to Traditional
• 50-cents-on-dollar match on next 2% you contribute: Goes to Traditional
• Total government contribution if you put in 5%: 5% of base pay, all Traditional

How Fast This Adds Up

An E-5 at 6 years of service earning roughly $40,000 in base pay gets $2,000/year in government contributions, all of it Traditional. Over a 20-year career with promotions, that match grows significantly.

Add 7% average annual growth, and an E-7 retiring at 20 years could have $80,000 or more in Traditional TSP from matching alone. That's $80,000 that will be taxed as ordinary income when withdrawn in retirement, potentially at a higher bracket than you're in today.

Tax Bracket Math: How Much to Convert

The core question: how much can you convert without jumping into a higher tax bracket? The answer depends on your rank, filing status, and spouse income.

2026 Federal Tax Brackets

2026 standard deduction: $16,100 (single) / $32,200 (married filing jointly)

Military members have a built-in advantage here. BAH, BAS, and other allowances are not taxable income. Only base pay, bonuses, and special pays count. An E-6 earning $49,000 in base pay plus $24,000 in BAH and $5,000 in BAS has a total compensation of $78,000 but only $49,000 in taxable income.

Your "Bracket Space": How Much Room You Have

Bracket space is the gap between your taxable income and the top of your current bracket. That's how much you can convert without spilling into the next rate.

For a married filing jointly filer, the 12% bracket ends at $100,800 in taxable income, which means $100,800 + $32,200 standard deduction = $133,000 in gross income. Subtract your base pay, and the remainder is your conversion room.

Worked Example: E-5 Single, Converting at 12%

• Base pay: ~$40,000/year
• Standard deduction: $16,100
• Taxable income: $23,900
• 12% bracket ceiling (single): $50,400
• Conversion space at 12%: $50,400 - $23,900 = $26,500

Converting $26,500 at a 12% marginal rate costs $3,180 in federal tax. If that money sits in Traditional TSP and grows at 7% for 20 years, it becomes roughly $102,500. Withdrawing $102,500 at 22% in retirement costs $22,550 in tax. Converting now saves you $19,370.

Four Best Windows for Conversions

1. Early Career (E-1 through E-4)

An E-3 at 3 years earns roughly $30,000 in base pay. After the $16,100 standard deduction (single), taxable income is just $13,900, putting you in the 12% bracket. You have over $36,000 of conversion room before hitting 22%.

The catch: most junior enlisted don't have a large Traditional TSP balance yet. But if you've contributed to Traditional TSP for a few years, even converting $3,000 to $5,000 at 10-12% now is far cheaper than converting (or withdrawing) at 22-24% later.

2. Terminal Leave and Transition Year

The year you separate from service is often a low-income year. If you retire on July 1, you've earned roughly half your annual base pay. Your retirement pension is typically 40-50% of your active-duty pay. Your total income for that year is lower than any recent year, giving you more bracket space.

If you're retiring as an E-7 at 20 years: six months of active pay ($30,000) plus six months of pension ($17,800) equals $47,800 gross income. After the $32,200 MFJ deduction, taxable income is $15,600. You have $85,200 of 12% bracket space to use for conversions.

3. Years With Lower Spouse Income

If your spouse takes time off for a PCS move, goes back to school, or is between jobs, your household income drops temporarily. That opens up conversion space. An MFJ household with just one military income often has tens of thousands of dollars in room below the 22% bracket.

4. Combat Zone Deployment

This is the most powerful conversion window. If your entire pay is excluded under CZTE, your federal taxable income can be near zero, and conversions can be essentially tax-free. We cover this strategy in depth (with 6-month and 12-month examples) in our TSP Roth + CZTE guide.

In-Plan Conversion vs. Roth IRA Rollover

Before January 2026, the Roth IRA rollover was your only option. Now you have both. Here's how they compare.

Use the in-plan conversion if: You're still serving, you want to keep the G Fund, and you want TSP's near-zero fees. This is the right choice for most active-duty members.

Use the Roth IRA rollover if: You've separated from service and want broader investment options (individual stocks, sector ETFs, or real estate funds) that the TSP doesn't offer.

You can also combine both. Convert some match dollars in-plan each year while serving, then roll any remaining Traditional balance to a Roth IRA after separation.

The Two Five-Year Rules

Roth accounts have two separate five-year requirements. They work differently, and confusing them can lead to unnecessary penalties.

Rule 1: The Roth TSP Aging Rule

Your Roth TSP has one five-year clock. It starts on January 1 of the year you first contributed to Roth TSP (or made your first conversion, whichever is earlier). After five calendar years, the clock is satisfied. This clock does not restart with each new contribution or conversion.

If you first contributed to Roth TSP in 2023, your five-year clock is satisfied on January 1, 2028.

Rule 2: The Conversion Penalty Rule

If you withdraw converted amounts before age 59.5 and before the conversion is five years old, you may owe a 10% early withdrawal penalty on the taxable portion of the conversion. Each conversion starts its own five-year clock.

This mainly matters if you plan to access the money before age 59.5. If you're converting for long-term retirement, both rules are satisfied well before you start withdrawing.

Five Costly Mistakes

1. Converting Too Much and Jumping Brackets

A $50,000 conversion doesn't replace your salary. It stacks on top of it. An E-6 married filing jointly with $49,000 in base pay has $16,800 in taxable income after the standard deduction. Converting $50,000 pushes taxable income to $66,800, still in the 12% bracket. But converting $90,000 pushes taxable income to $106,800, putting $6,000 into the 22% bracket. That $6,000 costs $1,320 at 22% instead of $720 at 12%, an extra $600 in tax you could have avoided by converting $84,000 instead.

Calculate your bracket space first. Convert up to that line and stop.

2. Forgetting Quarterly Estimated Taxes

The TSP does not withhold taxes on conversions. If you convert $20,000 and owe $2,400 in additional tax, the IRS expects you to pay as you go, not wait until April. Estimated tax payments are due quarterly: April 15, June 16, September 15, and January 15. Underpayment triggers a penalty.

One workaround: increase the withholding on your regular paycheck (adjust your W-4) to cover the conversion tax. This avoids quarterly filing.

3. Ignoring State Taxes

You owe state income tax on conversions in the state where you're a legal resident at the time of conversion. If you're a Florida or Texas resident (no state income tax), conversions cost nothing at the state level. If you're a California resident, you're paying up to 13.3% state tax on top of federal.

If you're PCSing from a high-tax state to a no-tax state, wait until you've established residency in the new state before converting. It can save thousands.

4. Using TSP Money to Pay the Tax Bill

You cannot pull money from the TSP to pay the tax on your conversion. If you try to take a withdrawal for tax payments, that withdrawal is itself a taxable event (and may trigger a 10% early withdrawal penalty). You need cash outside the TSP to cover the bill.

Before converting, make sure you have enough in savings or can increase your paycheck withholding to cover the tax.

5. Waiting for the "Perfect" Time

Some people wait for a market dip to convert, thinking they'll pay less tax on a smaller balance. The problem: you can't predict dips, and while you wait, your Traditional balance grows, meaning more taxable money later. A consistent annual conversion (sized to your bracket space) beats trying to time the market.

How to Convert on TSP.gov

1. Log in to your TSP account at tsp.gov
2. Go to Investing Strategies in the main menu
3. Select Roth In-Plan Conversions
4. Choose the contribution source to convert from (employee contributions, agency match, agency automatic 1%)
5. Enter the dollar amount (minimum $500)
6. Review and confirm

Conversions submitted before noon ET are processed the same business day. You'll receive a confirmation, and your balance will reflect the change within 1-2 days. The TSP reports the conversion on your annual 1099-R.

Frequently Asked Questions

Can I convert my TSP while still on active duty?

Yes. The in-plan conversion feature works for active duty, Guard, Reserve, and separated members. You do not need to separate from service to convert.

Do conversions count against my annual TSP contribution limit?

No. Conversions are a separate transaction from contributions. Your $24,500 elective deferral limit for 2026 is unaffected by conversions.

Can I undo a Roth conversion if the market drops?

No. TSP Roth in-plan conversions are irrevocable. The Tax Cuts and Jobs Act eliminated recharacterization for Roth conversions in 2018. Once processed, it cannot be reversed.

Should I convert if I'm deploying to a combat zone?

A combat zone deployment can make conversions nearly tax-free because of CZTE. This is the most powerful conversion scenario for military members. See our TSP Roth + CZTE guide for the full strategy.

Does my BRS match keep going to Traditional after I convert?

Yes. Each pay period's BRS matching contributions go to your Traditional TSP balance regardless of past conversions. You'll need to convert new match dollars periodically.

How do I figure out my current tax bracket?

Check your most recent LES for year-to-date taxable wages. Subtract the standard deduction ($16,100 single, $32,200 MFJ for 2026). Compare the result to the bracket table above. Only base pay, bonuses, and other taxable income count. BAH and BAS are not taxable.

What is the minimum and maximum conversion amount?

Minimum $500 per conversion. No maximum dollar amount, but you can only do 26 conversions per calendar year. You must leave at least $500 in each Traditional contribution source after converting.

Do I need to make estimated tax payments after converting?

If the tax from your conversion significantly exceeds your paycheck withholding, yes. The TSP does not withhold taxes on conversions. Use IRS Form 1040-ES. Quarterly deadlines: April 15, June 16, September 15, and January 15. Alternatively, increase your W-4 withholding to cover the extra tax.

Related Articles

• TSP Roth Conversions + CZTE: Tax-Free Military Millionaire Strategy
• Tariffs and Your TSP 2026: A Military Member's Guide
• Military Retirement Taxes 2026: Complete Guide
• 10 Post-Military Income Mistakes
• BRS Lump Sum vs Annuity 2026: The $500K Decision

This article is for educational purposes. Individual circumstances vary. Consult a tax advisor or financial planner before making Roth conversion decisions.