TSP Roth In-Plan Conversions: How CZTE Can Help You Build a "Tax-Free Military Millionaire" Plan

📅 January 6, 2026 18 min read TSP Strategy

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New for 2026: Starting January 28, 2026, the Thrift Savings Plan (TSP) will allow Roth in-plan conversions—meaning you can convert some of your Traditional TSP balance into your Roth TSP without leaving the plan.

If you're in the Blended Retirement System (BRS) and you ever deploy to a Combat Zone Tax Exclusion (CZTE) area, this is one of the most powerful "legal loopholes" in military finance.

📊 Quick Takeaway: A service member deploying for 12 months can potentially put $77,000-$80,000+ into tax-free Roth accounts in a single year—building what could grow to over $1.3 million in tax-free retirement wealth over 30 years. Even a 6-month deployment can create over $1 million in tax-free money.

What Is a TSP Roth In-Plan Conversion?

A Roth in-plan conversion lets you move money from Traditional TSP (pre-tax)Roth TSP (after-tax) inside your TSP account.

This matters because Roth money (when qualified) can be withdrawn tax-free in retirement. So the game becomes: Pay little-to-no tax now → lock in tax-free growth later.

Why This Is a Game-Changer for Military Members

Before January 28, 2026, if you wanted to convert Traditional TSP to Roth, you had to leave the TSP system, roll it to a Traditional IRA, then convert to Roth IRA (triggering taxes). Now you can do it all within TSP—simpler, cleaner, and with lower administrative costs.

Why This Is Huge for BRS (and Anyone With Traditional TSP Money)

If you're in the Blended Retirement System, you likely have Traditional TSP dollars even if you've been "Team Roth" your whole career, because:

So BRS members naturally build a Traditional TSP balance that can now be converted.

💡 Important BRS Note: The 5% BRS match (1% automatic + up to 4% matching) goes into Traditional TSP and counts toward the $72,000 annual additions limit. This means if you're maximizing contributions in a CZTE year, your personal contributions (Roth + Traditional) plus the government match cannot exceed $72,000 total.

Why CZTE Is the Cheat Code

A CZTE can make all (or part) of your military pay federal income tax-free for qualifying months. This creates a rare combo of:

  1. Very low taxable income, and
  2. Very high retirement contribution capability

That's where Roth conversions shine. You can contribute massive amounts to Traditional TSP (tax-free because of CZTE), then convert those dollars to Roth while your overall taxable income is near zero.

What Is Combat Zone Tax Exclusion (CZTE)?

CZTE is an IRS provision that excludes military pay from federal income tax when you serve in designated combat zones. This includes:

Not included: BAH and BAS (already tax-free)

⚠️ Important for Officers: Commissioned officers have a monthly CZTE cap equal to the highest enlisted pay rate (approximately $10,295 for 2026) plus Hostile Fire/Imminent Danger Pay ($225). This means an O-4 earning $100k in base pay won't have all income excluded—only approximately $10,520 per month qualifies for CZTE.

For enlisted members, warrant officers, and commissioned warrant officers, all military pay for each month in a combat zone is excluded from federal taxation.

Should I Do a TSP Roth Conversion in My CZTE Year?
Start: You're deploying to a Combat Zone (CZTE)
Are you in the Blended Retirement System (BRS)?
YES
✓ You have Traditional TSP from BRS match + 1% automatic

Perfect for conversions!
NO (High-3)
✓ Do you have Traditional TSP from past contributions?

If YES, conversions can still work!
Can you contribute beyond the $24,500 elective deferral limit?
YES
🚀 Maximum Strategy:

1. Max Roth TSP: $24,500
2. Add Traditional TSP up to $72k total
3. Convert monthly to Roth
4. Fund Roth IRAs

Potential: $70k-$80k+ in Roth!
NO
✓ Basic Strategy:

1. Contribute what you can to Roth TSP
2. Convert existing Traditional TSP during low-tax CZTE year
3. Fund Roth IRAs if possible

Still powerful!
Do you have cash outside TSP to pay conversion taxes?
YES
✓ GREEN LIGHT!

You're ready to execute the strategy starting Jan 28, 2026
NO
⚠️ WAIT

Build emergency fund first. Never use TSP money to pay conversion taxes.

The 2026 Limits You Need to Know (Plain English)

There are two "big" limits people confuse:

1) Elective Deferral Limit (Your normal TSP contribution limit)

2) Annual Additions Limit (the "deployment max" limit)

Key CZTE rule: Roth TSP contributions are limited to the elective deferral limit ($24,500), so if you contribute beyond that while deployed, the extra typically ends up in Traditional TSP and is marked as "tax-exempt."

3) Catch-Up Contributions

How to Hit the $72,000 Annual Additions Limit in a CZTE Year
$72,000
Maximum Total TSP Contributions (2026 Annual Additions Limit)
Your Roth TSP:
$24,500
Your Traditional TSP (CZTE):
$42,500
BRS Match (5%):
$5,000
💡 Key Point: The BRS match counts toward the $72,000 limit, so your personal contributions can be up to $67,000 to stay within the cap.

Then Convert to Maximize Roth:

Traditional TSP Balance
$47,500
($42,500 tax-exempt + $5,000 taxable)
Convert Monthly
~$42,500
Pro-rata: mostly tax-exempt!
Final Roth TSP Balance: ~$67,000
($24,500 direct + ~$42,500 converted)
💰 Add Roth IRAs: Another $15,000-$17,200 (you + spouse)
🎯 Total Roth in One Year: $80,000+

Pro-Rata Rule (The One Detail That Changes Everything)

Conversions are pro-rata. That means conversions include a proportional mix of taxable and tax-exempt dollars based on your entire Traditional TSP balance.

You can't "pick only the tax-exempt portion."

Understanding Pro-Rata With Examples

Example 1: Simple Pro-Rata

Example 2: Heavy Tax-Exempt Balance

Why Pro-Rata Actually Helps You: While you can't cherry-pick only tax-exempt dollars, the pro-rata rule actually works in your favor during CZTE years because most of your Traditional TSP is tax-exempt (from CZTE contributions), your overall taxable income is already low (due to CZTE), and the small taxable portion gets taxed at very low rates (often 0% or 10%).

Scenario 1: 12-Month CZTE Deployment (The "Roth Rocket Fuel" Year)

Let's use a clean, realistic example:

If your pay is CZTE-eligible for the whole year, your federal taxable income can be extremely low—sometimes near zero after the standard deduction.

The Setup (One Simple Way)

  1. Max Roth TSP up to the elective deferral limit ($24,500)
  2. Put the rest (up to the annual additions limit) into Traditional TSP while in CZTE
  3. Convert monthly from Traditional → Roth
  4. Also fund two Roth IRAs (you + spouse)

Complete Example with Numbers

Total Income:

TSP Contribution Strategy:

How to Set Your Contributions:

Breakdown:

Monthly Conversions:
Throughout the year, you convert your Traditional TSP balance to Roth. Because of the pro-rata rule, converting $42,500: approximately $37,850 is tax-exempt, $4,650 is taxable.

Roth IRAs:

What This Can Build in One Year

Conservative estimate (both under 50):

Taxes Owed

Even though you converted Traditional TSP, your taxable income for the year might look like:

You may owe zero federal income tax for the year while building a massive Roth balance.

What Happens Over 30 Years?

If $77,350 grows at 10% average annual return for 30 years:

Breaking Down the Math:

All growing completely tax-free, with no Required Minimum Distributions (RMDs).

12-Month CZTE Deployment: Month-by-Month Strategy
January
• Set TSP contributions: 21% Roth + 34% Traditional
• Fund Roth IRA: $625
• First conversion: ~$3,500
Total saved this month: ~$8,000
1
2
February - March
• Continue TSP contributions
• Monthly Roth IRA: $625/month
• Monthly conversions: ~$3,500
Running total: ~$24,000 in Roth
April - June (Q2)
• Make Q1 estimated tax payment (if needed)
• Continue monthly conversions
• Stay on track with contributions
Running total: ~$40,000 in Roth
3
4
July - September (Q3)
• Hit $24,500 Roth TSP limit around mid-year
• Traditional TSP continues automatically
• Keep converting monthly
Running total: ~$55,000 in Roth
October - December (Q4)
• Final conversions of the year
• Complete Roth IRA contributions
• Make Q4 estimated tax payment
FINAL: ~$80,000 in Roth accounts! 🎉
5
📊
Tax Time (Next April)
• Federal taxable income: ~$5,000
• After standard deduction: $0 taxable
• Federal tax owed: $0
Built $80k+ in Roth for $0 in taxes!
🔑 Success Factors:
  • Convert monthly (not once at year-end) to minimize taxable growth
  • Set contributions to hit $72,000 by December
  • Make quarterly estimated tax payments to avoid penalties
  • Keep emergency fund intact—never use TSP money for taxes

Scenario 2: 6-Month CZTE Deployment (Still Insanely Powerful)

Now let's say you're in a CZTE from January through June.

You can still do a strong version of the strategy:

Example with Numbers

Income:

TSP Strategy:

Roth IRAs: $15,000 (or $17,200 if both 50+)

What You Might Build

Total in Roth accounts (under 50):

Why Taxes Can Still Be Tiny

Your taxable income for the year:

At 2026 rates, married filing jointly, you'd pay approximately $2,205 in federal tax—an effective federal tax rate of about 4% while putting over $60k into Roth accounts.

6-Month Deployment 30-Year Projection

If $60,250 grows at 10% average annual return for 30 years: ~$60,250 → ~$1.05M. With a 4% withdrawal rate → ~$42,000/year tax-free.

Even a 6-month deployment can create over $1 million in tax-free retirement wealth!

6-Month vs. 12-Month CZTE Deployment Outcomes
6-Month Deployment
CZTE Income:
$50,000
Taxable Income:
$50,000
Roth TSP Direct:
$24,500
Traditional TSP (CZTE):
~$25,000
BRS Match:
$5,000
Converted to Roth:
~$20,750
Roth IRAs (both):
$15,000
Total Roth: ~$60,250
Estimated Taxes:
Taxable income after deduction: ~$22,000
Federal tax: ~$2,200
Effective rate: ~4%
12-Month Deployment
CZTE Income:
$100,000
Taxable Income:
$0
Roth TSP Direct:
$24,500
Traditional TSP (CZTE):
~$42,500
BRS Match:
$5,000
Converted to Roth:
~$37,850
Roth IRAs (both):
$15,000
Total Roth: ~$77,350
Estimated Taxes:
Taxable income after deduction: ~$0
Federal tax: ~$0
Effective rate: 0%! 🎉

30-Year Growth Projection (10% avg. annual return)

6-Month Deployment
$1.05M
Tax-free at withdrawal
vs.
12-Month Deployment
$1.35M
Tax-free at withdrawal
4% Safe Withdrawal Rate:
6-Month = $42,000/year tax-free | 12-Month = $54,000/year tax-free
💡 Key Insight: Even a 6-month deployment can generate over $1 million in tax-free retirement wealth. A full-year deployment can create nearly $1.4 million. This is one of the most powerful wealth-building opportunities available to service members.

Practical Tips (So You Don't Get Burned)

1) Consider converting monthly

If the market rises during the year, waiting until December could mean converting more earnings (which can be taxable if they're tied to taxable Traditional dollars). Monthly conversions can reduce the "oops, my taxable growth ballooned" problem.

Recommended approach:

2) Know the TSP conversion guardrails

TSP Conversion Rules (Confirmed for 2026 Launch):

3) State taxes still matter

While federal income may be tax-free during CZTE, state taxes on Roth conversions vary by state. Some states may still tax Roth conversions even if the original income was CZTE-excluded at the federal level.

States with no income tax (best for conversions):
Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming

States that fully exempt military pay:
Alabama, Hawaii, Illinois, Kansas, Massachusetts, Michigan, Mississippi, New Jersey, Pennsylvania, Wisconsin

Check your state's tax treatment with our state-by-state military retirement tax guide.

4) Make estimated tax payments

Since TSP doesn't withhold taxes on conversions, you'll likely need to make quarterly estimated tax payments to avoid underpayment penalties.

Quarterly deadlines:

How This Fits Your Retirement Plan

This TSP Roth conversion strategy is most powerful when it connects to your overall military retirement plan:

Calculate Your Complete Military Retirement Income

See your exact monthly income including retirement pay, VA disability, and state tax impact. Understand how this TSP Roth strategy fits into your bigger picture.

Use the Free Calculator →

Calculating Your Military Retirement

High-3 System:

BRS System:

Adding VA Disability

VA disability is:

Example combined income:

Compare your retirement options across all 50 states: State-by-State Military Retirement Tax Guide

Frequently Asked Questions

Can I do this if I'm not in BRS?

Yes. BRS just makes it more common to have Traditional dollars (match + 1%). But anyone with Traditional TSP money may benefit. High-3 retirees with Traditional TSP balances can absolutely use this strategy.

If I'm in a CZTE, is everything automatically tax-free?

Not everything. CZTE applies to certain pay types (basic pay, special pays, bonuses signed in the combat zone) for qualifying months. Housing allowances (BAH) and subsistence allowances (BAS) are already tax-free. Rules differ for commissioned officers, who have a monthly cap.

Can I convert only the tax-exempt part?

No—conversions are pro-rata. TSP will automatically convert a proportional mix based on your entire Traditional balance.

Will conversions change my contribution limits?

No. Conversions are not "contributions." They're an internal transfer/conversion event. You can still max out your $24,500 elective deferral limit regardless of how much you convert.

Can I convert while I'm still on active duty?

Yes! Both active and separated TSP participants are eligible for Roth in-plan conversions starting January 28, 2026. You don't need to retire or separate to use this feature.

What if I'm deployed for only part of the year?

You can still benefit! A 6-month deployment can still generate substantial Roth savings (see Scenario 2 above showing how to build $60k+ in Roth accounts with a 6-month deployment).

How do I actually request a conversion?

Starting January 28, 2026, you'll be able to request conversions through your TSP account at tsp.gov. Log into My Account and follow the conversion instructions. TSP will provide detailed guidance when the feature launches.

Do state taxes apply to conversions?

It depends on your state of legal residence. Most states follow federal treatment (so CZTE would exclude it), but some states have different rules. Check our state-by-state guide for your specific state's treatment of military income and Roth conversions.

Bottom Line: Your Action Plan

Starting January 28, 2026, Roth in-plan conversions give service members a new way to move Traditional TSP dollars into Roth—without leaving TSP.

If you combine that with a CZTE year, you can potentially create a massive, long-term tax-free retirement bucket—the kind that turns one deployment year into decades of compounding.

The Math in Simple Terms

Single deployment year:

Over 30 years at 10% returns:

Your Next Steps

If you're deploying in 2026:

  1. Before deployment: Review this strategy with your spouse, calculate your target contribution percentages, ensure you have emergency fund to cover any taxes
  2. Month 1 of deployment: Update MyPay contributions to maximize toward $72k, set up automatic Roth IRA contributions, make your first TSP Roth conversion
  3. Monthly during deployment: Convert Traditional → Roth (approximately same amount each month), contribute to Roth IRAs, track totals toward annual limits
  4. End of deployment year: Final conversions in December, verify you hit your targets, gather tax documents for filing
  5. April (tax time): File tax return showing conversions, pay any remaining tax (should be minimal)

If you're not deploying soon:

  1. Run your retirement projections: MilitaryRetirementCalc.com
  2. Compare state tax impacts: State Tax Guide
  3. Build your Traditional TSP balance (so you have more to convert later)
  4. Save cash outside TSP for future conversion taxes
  5. Bookmark this guide for when you do deploy

Remember

This is one of the most powerful wealth-building opportunities available to service members. Don't leave this money on the table. A single deployment year, properly planned, can set up decades of tax-free retirement income.

That's financial freedom.

Disclaimer: This article is for educational purposes only and is not tax, legal, or financial advice. TSP rules, tax laws, and contribution limits are subject to change. Combat Zone Tax Exclusion eligibility depends on your specific deployment orders and location. Always consult with a qualified tax professional or financial advisor before making significant financial decisions.

Calculate Your Military Retirement Income

See your exact retirement pay, VA disability, and state tax impact. Understand how TSP fits into your complete retirement plan.

Use the Free Calculator →

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