What Happens If You Can’t Pay the Roth Conversion Tax? (w/Examples) + FAQs

This article reflects federal rules as of June 2026 and covers tax year 2025 (filed in 2026) with notes for tax year 2026. Tax law changes — confirm current figures before you file.

Quick Answer

You still owe the tax, and you cannot undo the conversion. Since 2018, a Roth conversion is permanent. If you can’t pay by the April 15, 2026 deadline for tax year 2025, file your return anyway, pay what you can, and set up an IRS payment plan to limit penalties and interest.

A Roth conversion moves money from a traditional IRA into a Roth IRA, and the whole converted amount counts as ordinary income for that year. The trouble starts when the tax bill arrives and the cash isn’t there — because the 2017 Tax Cuts and Jobs Act removed your ability to reverse the move, so you’re locked into the tax no matter how the market behaves afterward.

That single locked-in bill is why timing and planning matter so much. The IRS charges a failure-to-pay penalty of 0.5% per month plus interest that compounds daily, and for the third quarter of 2026 the underpayment interest rate is 7% — so a six-figure conversion can quietly grow your debt by hundreds of dollars every month you wait.

Here’s what you’ll learn:

• 🔒 Why you can’t recharacterize (undo) a conversion anymore — and what that locks you into.
• 💸 The exact penalties and daily-compounding interest the IRS adds when you can’t pay.
• 📋 Every IRS relief option, from short-term extensions to Offers in Compromise, ranked by who they fit.
• 🧮 Fully worked dollar examples showing the real cost of paying late.
• ⚠️ The seven mistakes that turn a manageable bill into a financial crisis.

What a Roth Conversion Tax Really Is

A Roth conversion is the act of moving pre-tax retirement money — usually from a traditional IRA, SEP-IRA, or SIMPLE IRA — into a Roth IRA. You pay tax now so the money grows tax-free and comes out tax-free in retirement. The catch is timing: the full converted amount is added to your taxable income in the year you convert, not spread out over time.

That income shows up on your Form 1040 and is taxed at ordinary rates, the same brackets that apply to wages. A large conversion can push you into a higher bracket, raise your Medicare premiums, and trigger phase-outs of other tax breaks. The conversion itself is reported to you on a Form 1099-R from your IRA custodian.

The reason people get stuck is simple. The tax is due for the year of the conversion, but the converted dollars are now sitting inside the Roth account, where pulling them back out to pay the tax can create new taxes and penalties. So the bill is real, it’s large, and the obvious source of cash is the one place you don’t want to touch.

Why the Tax Is Locked In Forever

Before 2018, you could “recharacterize” a conversion — basically hit undo and move the money back to a traditional IRA, erasing the tax. The 2017 Tax Cuts and Jobs Act ended that for conversions made on or after January 1, 2018.

The consequence is severe: once you convert, the income is permanent for that tax year, even if the Roth account loses value the next day. A reader who converts $100,000 in January 2026 and watches it fall to $70,000 by April still owes tax on the full $100,000. The misconception that you can “reverse a bad conversion” causes real damage every filing season. What you should do is treat a conversion as final the moment you submit it, and only convert an amount whose tax you can cover from outside funds.

Which Situation Applies to You?

The right move depends on where you are in the process. Find your situation below, then read the matching section.

• You already converted and the bill is here: Skip to the penalties and IRS relief sections. Your job is damage control.
• You’re planning a conversion this year: Read the safe-harbor and withholding sections first. Your job is prevention.
• You converted late in 2025 and underpaid: You may owe an underpayment penalty on top of the balance — see the safe-harbor section and Form 2210.
• Your income is now near zero (job loss, retirement): You may qualify for Currently Not Collectible status — see the relief section.
• The debt is far beyond what you can ever pay: An Offer in Compromise may settle it for less — see that section.

The Penalties When You Can’t Pay

Not paying a Roth conversion tax bill triggers three separate charges that stack on top of each other. Understanding each one tells you exactly how fast your debt grows and which problem to solve first.

The failure-to-pay penalty is the main one. The IRS charges 0.5% of the unpaid tax each month, or part of a month, up to a maximum of 25%. If you file on time and set up an installment agreement, that rate drops to 0.25% per month — a strong reason to file even when you can’t pay.

The failure-to-file penalty is far harsher and entirely avoidable. It runs 5% of the unpaid tax per month, up to 25%, and for returns more than 60 days late the minimum is the lesser of $510 or 100% of the tax due. Filing on time, even with zero payment, kills this penalty completely.

Finally, interest compounds daily on the unpaid balance. The first and third quarters of 2026 carry a 7% rate, while the second quarter dropped to 6%. Interest accrues on penalties too, so the longer you wait, the faster the snowball rolls.

The Underpayment Penalty Trap

A separate penalty hits if you didn’t pay enough during the year. Because conversion income often arrives without withholding, many people trip the underpayment of estimated tax penalty even before the April deadline.

You avoid it under “safe harbor” if you paid at least 90% of the current year’s tax, or 100% of last year’s tax (110% if your prior-year AGI topped $150,000). Miss that, and the IRS calculates a penalty using the same quarterly interest rates. The fix is to file Form 2210, sometimes with Schedule AI to show when the income actually arrived, or to plan withholding so you land inside the safe harbor before converting.

What the IRS Relief Options Actually Are

The IRS would rather collect over time than chase you, so it offers several formal programs. Each fits a different financial reality, and choosing the wrong one wastes fees and time.

A short-term payment plan gives you up to 180 days to pay in full with no setup fee, though penalties and interest keep running. This fits readers who can cover the bill within a few months — say, after a bonus or a property sale.

A long-term installment agreement lets you pay monthly for up to 72 months (sometimes longer). You request it online or with Form 9465. Setup fees range from $0 for low-income direct-debit plans up to roughly $130 online; direct debit lowers your monthly penalty rate to 0.25%.

An Offer in Compromise settles the debt for less than the full amount when you genuinely can’t pay it. You apply with Form 656 and Form 433-A (OIC), a $205 fee, and an initial payment. Currently Not Collectible (CNC) status pauses collection entirely when paying would leave you unable to afford basic living costs.

Comparing the IRS Programs

These programs differ sharply in who qualifies and what they cost. The table below shows the practical trade-offs.

Relief Option	Who It Fits and What It Costs
Short-term plan (≤180 days)	Can pay soon; no setup fee, penalties and interest still accrue
Long-term installment (Form 9465)	Owe under $50,000 and need months/years; up to ~$130 setup, monthly payments
Offer in Compromise (Form 656)	Debt exceeds ability to ever pay; $205 fee, settles for less
Currently Not Collectible	Income barely covers living costs; pauses collection, debt remains

How to Set Up an Installment Agreement

The fastest route is the Online Payment Agreement tool on IRS.gov, which approves most individual plans in minutes if you owe under $50,000 and have filed all returns. You choose a monthly amount and a payment date, and direct debit is strongly recommended because it cuts your penalty rate and prevents missed payments that default the agreement.

If you can’t use the online tool, file paper Form 9465 with your return or mail it to the address in the instructions. List the total you owe and your proposed monthly payment. Approval usually takes about 30 days. Missing a payment can void the deal and restart full collection, so set the payment low enough to always make it.

When CNC or an Offer Makes Sense

Currently Not Collectible status fits a reader whose income now barely covers rent, utilities, and food. You prove hardship with Form 433-F or Form 433-A, and the IRS pauses collection — though it keeps any future refunds and the debt still grows with interest. Review takes one to three months.

An Offer in Compromise fits a reader whose total debt dwarfs any realistic ability to pay. The IRS accepts an offer only when it doubts it can collect more, so documentation is everything. Both options usually warrant a tax professional, since a sloppy filing gets rejected and you lose the non-refundable fee.

Worked Examples With Real Numbers

Numbers make the cost concrete. These examples use 2025–2026 rates and assume the federal figures above.

Example 1 — Filing late vs. on time. Maria, a 58-year-old teacher in Ohio, converts $80,000 and owes $17,600 in federal tax (22% bracket) for tax year 2025. She can’t pay by April 15, 2026. If she fails to file for five months, her failure-to-file penalty alone is 5% × 5 × $17,600 = $4,400, plus interest. If instead she files on time and sets up a plan, her failure-to-pay penalty for those five months is just 0.25% × 5 × $17,600 = $220. Filing on time saves her about $4,180.

Example 2 — The cost of waiting a year. David, a 62-year-old retiree in Texas, owes $25,000 on a conversion and pays nothing for 12 months while on no plan. Failure-to-pay at 0.5% × 12 = 6%, or $1,500. Interest at roughly 7% compounded daily adds about $1,800. His $25,000 bill grows to roughly $28,300 — and the clock keeps running until paid.

Example 3 — The underpayment penalty. Priya, a 45-year-old consultant in California, converts $50,000 in November 2025 with no withholding. Her prior-year AGI was $200,000, so her safe harbor was 110% of last year’s tax. She missed it and owes an underpayment penalty computed at the quarterly rates on the shortfall, on top of her balance. Withholding 24% directly from the conversion would have avoided it entirely.

Scenario Outcomes

These three scenarios cover the most common ways the “can’t pay” problem plays out.

What You Do	What Happens Next
File on time, pay nothing, no plan	0.5%/month failure-to-pay plus 7% interest accrue until paid
Don’t file and don’t pay	5%/month failure-to-file stacks with failure-to-pay, up to 47.5% total
File on time, set up direct-debit plan	Penalty drops to 0.25%/month, collection actions paused

Federal vs. State Tax on a Conversion

The federal rules above are only half the bill. A Roth conversion is also taxed by most states that have an income tax, and your state has its own deadlines, penalties, and payment plans that do not mirror the IRS.

Conformity varies widely. States like California and New York tax conversion income at their own rates and run separate installment programs through their tax departments — California’s Franchise Tax Board, for example, offers its own payment plans with its own fees. No-income-tax states such as Texas, Florida, and Nevada impose no state tax on the conversion at all, which makes the federal bill the only worry.

The practical step is to confirm your state’s treatment before converting and check whether it offers a payment plan if you fall short. Never assume your state follows the federal rate, deadline, or relief option — guessing here can leave a second unpaid balance growing at the state level.

Mistakes to Avoid

Each of these errors carries a specific, avoidable cost.

• Not filing because you can’t pay. This triggers the 5%/month failure-to-file penalty — ten times the failure-to-pay rate.
• Paying the tax from the IRA itself. If you’re under 59½, withheld or withdrawn IRA funds can trigger a 10% early-withdrawal penalty.
• Assuming you can undo the conversion. Recharacterization of conversions ended in 2018; the income is permanent.
• Converting late in the year with no withholding. This commonly trips the underpayment penalty under the safe-harbor rules.
• Ignoring the safe harbor. Failing to pay 100% (or 110%) of last year’s tax invites an estimated-tax penalty even if you pay by April.
• Defaulting on an installment agreement. A single missed payment can void the plan and restart full collection.
• Converting an amount you can’t cover with outside cash. This is the root cause of most “can’t pay” crises — convert only what you can fund from non-retirement money.

Do’s and Don’ts

• Do file your return on time, even with no payment, because it erases the worst penalty.
• Do pay something now, since penalties and interest apply only to the unpaid portion.
• Do use direct debit on a plan, because it cuts your penalty rate to 0.25%.
• Do withhold tax from the conversion if converting late, to stay inside the safe harbor.

• Do call a professional for large debts, because Offers and CNC filings fail without solid documentation.

• Don’t raid the Roth to pay the tax, because it undoes the benefit and may trigger penalties.

• Don’t ignore IRS notices, since silence speeds up levies and liens.
• Don’t convert more than you can fund, because the bill can’t be reversed.
• Don’t assume your state follows federal rules, as conformity and deadlines differ.
• Don’t wait for a bigger bill, because daily-compounding interest only grows.

Pros and Cons of Each Payment Path

• Pro — Installment agreement: Spreads the bill over years and pauses aggressive collection.
• Pro — Short-term extension: No setup fee if you can pay within 180 days.
• Pro — Offer in Compromise: Can settle a hopeless debt for far less.
• Pro — CNC status: Stops collection when you truly can’t afford to pay.

• Pro — Filing on time: Instantly avoids the 5%/month failure-to-file penalty.

• Con — Installment agreement: Interest and penalties keep accruing until paid.

• Con — Short-term extension: Doesn’t reduce penalties, only delays full payment.
• Con — Offer in Compromise: Low acceptance odds and a non-refundable fee.
• Con — CNC status: Debt and interest keep growing, and refunds are seized.
• Con — Doing nothing: Levies, liens, and the maximum stacked penalties.

What to Do Next

Take these steps in order if you can’t pay your conversion tax.

1. File your tax return by April 15, 2026, even if you can’t pay a dime.
2. Pay as much as you can now to shrink the base that penalties and interest hit.
3. Apply online for a payment plan through the Online Payment Agreement tool or file Form 9465.
4. Choose direct debit to drop your penalty rate and avoid default.
5. Check your state’s rules and set up a separate state plan if needed.
6. Gather financial records (income, expenses, assets) if you’ll seek CNC or an Offer.
7. Call a tax professional if the debt is large, you face a levy, or you’re considering an Offer in Compromise.

This article is educational and not a substitute for advice from a licensed CPA, enrolled agent, or tax attorney for your specific situation. A large conversion debt, a pending levy, or an Offer in Compromise is complex enough to warrant professional help, which typically involves reviewing your finances and negotiating directly with the IRS on your behalf.

FAQs

Can I undo a Roth conversion if I can’t pay the tax? No. Recharacterization of conversions ended January 1, 2018. The income is permanent for the conversion year, even if the account later loses value, so you must find another way to handle the bill.

What is the failure-to-pay penalty for tax year 2025? 0.5% of the unpaid tax per month, up to 25%. It drops to 0.25% per month once you file on time and enter an installment agreement, which is why filing matters even when you can’t pay.

What is the IRS interest rate right now? 7% for the third quarter of 2026, compounded daily on individual underpayments. The second quarter of 2026 was 6%, and rates reset every quarter, so confirm the current figure before estimating your cost.

Should I file my return if I can’t pay? Yes. Always file by the deadline. The failure-to-file penalty is 5% per month — ten times the failure-to-pay rate — and filing on time avoids it entirely while you arrange payment.

Can I pay the tax out of the converted Roth money? No, not safely. Pulling funds from the IRA or Roth to pay the tax can trigger a 10% early-withdrawal penalty if you’re under 59½ and undoes the conversion’s benefit.

How long can I take to pay the IRS? Up to 72 months under a standard long-term installment agreement, and sometimes longer. Short-term plans give you 180 days. You request these online or with Form 9465.

What is the safe harbor for a Roth conversion? Pay 100% of last year’s tax (110% if AGI over $150,000), or 90% of this year’s. Meeting it avoids the underpayment penalty regardless of when your conversion income arrived during the year.

Will the IRS settle my conversion tax for less? Sometimes, through an Offer in Compromise. The IRS accepts an offer only when it doubts it can collect the full amount. You apply with Form 656 and a $205 fee, and acceptance is far from guaranteed.

Does my state tax a Roth conversion? Usually yes, unless you live in a no-income-tax state. States like Texas and Florida impose no tax, while California and New York tax conversion income at their own rates with separate deadlines and plans.

What happens if I just ignore the bill? The IRS escalates to liens and levies. Penalties stack toward 47.5%, interest compounds daily, and the agency can garnish wages or seize bank funds. Ignoring notices is the costliest path available.

Can I get the penalty removed? Yes, sometimes. First-time penalty abatement may erase a penalty if you have a clean compliance history. You can also request a waiver on Form 2210 if your underpayment came from late-year conversion income.

What is Currently Not Collectible status? A temporary pause on IRS collection when paying would leave you unable to afford basic living costs. The debt and interest still grow, and the IRS keeps your refunds, but active collection stops while you qualify.

Word count: approximately 2,950 words.