Does a Roth Conversion Affect ACA Premium Subsidies? (w/Examples) + FAQs

This article reflects federal rules as of June 2026 and covers tax year 2026 (the 2026 plan year and the 2026 filing season). State rules are noted where they differ. Tax law changes fast right now — confirm current figures before you file or convert.

Quick Answer

Yes. A Roth conversion raises your Modified Adjusted Gross Income (MAGI), and ACA premium subsidies fall as MAGI rises. For tax year 2026, going $1 over 400% of the federal poverty level triggers the “subsidy cliff” and you lose every dollar of premium tax credit.

Why This Matters Right Now

A Roth conversion moves money from a pretax retirement account into a Roth account, and you pay income tax on the amount you move. That extra income lands in your MAGI, the income figure the IRS uses to size your Affordable Care Act (ACA) premium tax credit. When your MAGI goes up, your subsidy goes down — and for the 2026 plan year, the boosted pandemic-era subsidies have expired, so the old 400% FPL cliff is back.

This is a high-stakes squeeze for early retirees who buy coverage on the Marketplace before Medicare starts at 65. The enhanced credits from the American Rescue Plan and Inflation Reduction Act ended after 2025, so for 2026 a household even $1 above 400% FPL gets zero federal help. The Urban Institute warned that reinstating this cliff would make coverage unaffordable for many middle-income families, and a 60-something couple can face a swing of $20,000 or more in a single year by crossing one income line.

Here is what you will learn:

💸 How a Roth conversion changes the exact MAGI number that sets your subsidy.
📉 What the 2026 “subsidy cliff” is and the precise income lines that trigger it.
🧮 Three fully worked dollar examples, including a couple who loses $24,000 over one extra dollar.
🪜 How to “fill the bracket” with a Roth conversion ladder without blowing up your credit.
⚠️ The repayment trap on Form 8962 that can bill you back every advance dollar in 2026.

What a Roth Conversion Is — and Why It Touches Your Subsidy

A Roth conversion is when you move money from a traditional (pretax) IRA or 401(k) into a Roth account. You voluntarily pay income tax now so the money grows tax-free and comes out tax-free later. People do it to lower future required minimum distributions, to cut lifetime taxes, and to leave tax-free money to heirs.

The catch is that the converted amount is treated as ordinary income in the year you convert. That income flows onto your Form 1040, raises your Adjusted Gross Income (AGI), and therefore raises your MAGI. Because the ACA premium tax credit is calculated from MAGI, a conversion that helps your tax picture can shrink or destroy your subsidy in the same year.

The consequence is real money. If a conversion pushes your MAGI from 380% to 405% of poverty, you do not just lose a slice of your credit — under the 2026 cliff you lose all of it. The fix is to know your numbers before you convert, not after, because a Roth conversion generally cannot be undone once it is done — recharacterizing a conversion was banned by the 2017 tax law.

How ACA MAGI Is Actually Calculated

ACA MAGI is not the same MAGI used for IRA deductions or for Medicare’s IRMAA surcharge. Under the Affordable Care Act rules, ACA MAGI starts with your AGI and adds back three items: non-taxable Social Security benefits, tax-exempt (municipal bond) interest, and excluded foreign earned income.

This matters for retirees in a way most people miss. Your full Social Security benefit counts toward ACA MAGI, even the part that is not taxed on your 1040. Tax-free muni-bond interest counts too. So a couple who feels “low income” because much of their cash is tax-free can still sit close to the cliff before they convert a single dollar.

A Roth conversion adds straight to AGI, so it adds straight to ACA MAGI dollar for dollar. The consequence is simple math: a $30,000 conversion raises your ACA MAGI by $30,000. A common misconception is that Roth withdrawals also count — they do not. Once your Roth is at least five years old and you are over 59½, qualified Roth withdrawals add nothing to MAGI, which is exactly why converting before you need ACA coverage can pay off.

The 2026 Subsidy Cliff: The Numbers That Control Everything

For tax year 2026, premium tax credits are available to households with MAGI between 100% and 400% of the federal poverty level (FPL). The 2025 poverty guidelines set these 2026-coverage limits, and the HealthCare.gov figures confirm the base amounts used for the 48 contiguous states.

Here are the 2026 income lines that decide eligibility, drawn from the 2026 eligibility chart:

Household Size	400% FPL Cliff (Subsidy Lost Above This)
1 person	$62,600
2 people	$84,600
3 people	$106,600
4 people	$128,600

Above those lines, the federal credit is $0 for 2026. Two more 2026 changes raise the stakes. First, the applicable percentage rose — the top band (300–400% FPL) now caps your premium at 9.96% of income, up from 8.5% in 2025, so even below the cliff you pay more. Second, the repayment cap is gone: for 2026, if you took advance credits and then crossed 400% FPL, you must repay every dollar on Form 8962, with no $750–$3,150 protection that existed before.

Note this is partly unsettled. These 2026 rules reflect current law after the enhanced subsidies expired at the end of 2025. Congress could still act, so the healthcare.org analysts and others advise confirming the live figures before you convert.

Which Situation Applies to You?

The right move depends on where you sit relative to the cliff and whether you even use ACA coverage. Use this branch to find your case.

You are on Medicare or have job-based coverage. ACA subsidies do not apply to you, so a Roth conversion will not touch a premium credit — but it can still raise your Medicare IRMAA two years later. Skip to the IRMAA note in the FAQs.
You buy ACA coverage and your MAGI is far below 400% FPL. You may have room to convert up to the cliff and still keep some credit. See the “Roth conversion ladder” section.
You buy ACA coverage and sit just under 400% FPL. This is the danger zone. Even a small conversion can cost you the entire subsidy. Read the worked examples closely.
You buy ACA coverage and are already over 400% FPL. You get no 2026 credit regardless, so a conversion costs you nothing in subsidy terms — this may be your best year to convert aggressively.

Worked Example 1: The Couple Who Crossed the Cliff

Meet Frank and Donna, both 62, retired in Texas, with two on a Marketplace silver plan. Their 2026 ACA MAGI before any conversion is $80,000, which is about 378% of the $84,600 cliff for a household of two. At that income their plan costs them about 9.96% of MAGI, roughly $7,968 a year, with the rest covered by a premium tax credit.

Their full unsubsidized premium for the 62-year-old couple runs about $32,000 a year, so the credit is worth roughly $24,000. Frank decides to convert $10,000 from his traditional IRA to “use up a low bracket.” That conversion pushes their ACA MAGI to $90,000 — over the $84,600 cliff.

Result: they fall off the cliff and lose the entire $24,000 credit for 2026. Worse, because they took those credits in advance, the 2026 no-cap rule forces them to repay all of it on Form 8962. A $10,000 conversion cost them about $24,000 in lost subsidy plus income tax on the conversion itself.

Move	Frank and Donna’s 2026 Outcome
Skip the conversion (MAGI $80,000, ~378% FPL)	Keep ~$24,000 premium credit; pay ~$7,968 toward premiums
Convert $10,000 (MAGI $90,000, ~426% FPL)	Lose all $24,000 credit; repay advance credits in full on Form 8962

Worked Example 2: The Single Retiree With Room to Convert

Meet Maria, 58, single, retired early in Florida and covered by a Marketplace plan. Her 2026 ACA MAGI is only $30,000, about 192% of the $62,600 single cliff. She wants to convert traditional IRA money before her Roth turns into a tax-free bucket.

The 400% line for one person in 2026 is $62,600, so Maria has $32,600 of headroom before she falls off the cliff. She converts $25,000, lifting her MAGI to $55,000 (about 351% FPL). She stays under the cliff and keeps a credit, though a smaller one because her applicable percentage rises as income climbs.

The consequence is a careful trade. Maria pays tax on the $25,000 now and gives up some subsidy this year, but she keeps some credit, fills a low tax bracket, and shrinks future MAGI. The mistake to avoid is overshooting: one extra conversion dollar above $62,600 would erase her whole credit, so she leaves a safety margin of a few thousand dollars for stray interest or dividends.

Worked Example 3: The Roth Conversion Ladder

Meet James and Lin, both 60, who retired with a large traditional IRA and live on cash savings plus ACA coverage. Their “natural” 2026 ACA MAGI is just $25,000. They want to convert their IRA over several years before Medicare, but not blow the cliff.

The household-of-two cliff is $84,600, so in theory they could convert up to about $59,600 in one year and still stay under. Instead they choose a ladder: they convert a smaller amount each year — say $40,000 annually — keeping MAGI near 250% FPL where the subsidy is still meaningful and the cost-sharing reductions (extra savings below 250% FPL) are not fully lost.

The why: spreading conversions over five or six years lets them keep partial subsidies each year, smooths their tax brackets, and drains the IRA before age 65, when Medicare and its IRMAA surcharge replace ACA coverage. The named lesson is that the biggest one-year conversion is rarely the smartest one when you depend on a subsidy.

ACA Subsidy vs. Lifetime Tax Savings: How to Decide

The real question is whether the long-term tax saved by converting beats the short-term subsidy lost. A Bogleheads discussion shows couples weighing a $1,000-a-month premium swing against future bracket savings, and the answer flips depending on the dollars.

Convert more when your subsidy is small or already gone (you are over 400% FPL anyway), when you are in a very low tax bracket now, or when future RMDs would push you into a high bracket later. Convert less when your subsidy is large, when you sit just under the cliff, or when the lost credit clearly outweighs the bracket savings. A useful rule of thumb from Boldin’s analysis is to model both paths in a calculator before you convert, because the cliff makes the math jump, not glide.

Timing matters too. The conversion counts in the calendar year you do it, and you have until December 31 to act for that tax year — there is no extension. So early retirees often run a December projection of their MAGI, then convert only the gap that keeps them safely under their target FPL line.

Form 8962 and Form 8606: The Paperwork

Two IRS forms tie this together. You report the Roth conversion on Form 8606, which tracks the taxable amount of the conversion and any nondeductible basis, and the taxable figure flows to your 1040 and into your MAGI.

You reconcile your premium tax credit on Form 8962, filed with your return. Form 8962 compares the advance credit you received during the year against the credit your final MAGI actually allows. If your conversion pushed MAGI over 400% FPL, line by line the form will show excess advance credit, and for 2026 you repay all of it — there is no cap.

The consequence of skipping Form 8962 is severe: the IRS can hold your refund and bar future advance credits until you file it. The next step is simple — keep your Form 1095-A from the Marketplace, your conversion records, and a year-end MAGI estimate, then have your preparer run Form 8962 before you finalize any December conversion. (See our guides on how to fill out Form 8962 and how to fill out Form 8606 for line-by-line help.)

State Rules: Conformity and Extra Subsidies

Start with the federal baseline: the premium tax credit is a federal credit, and the 400% FPL cliff is federal. But states add two wrinkles. First, several states with their own marketplaces — including California’s Covered California — have offered state subsidies that can soften or remove the federal cliff for some residents, so a Californian over 400% FPL may still get state help that a Texan does not.

Second, state income tax on the conversion itself varies sharply. A no-income-tax state such as Texas or Florida charges $0 state tax on a Roth conversion, while California taxes the conversion as ordinary income at rates up to 13.3%. So the same $50,000 conversion can cost a Californian several thousand more than an identical retiree in Florida.

The lesson is to separate the two questions. Ask “does my state add its own ACA subsidy or cliff fix?” and “does my state tax the conversion?” — because the answers come from different agencies (your state marketplace versus your state revenue department) and can point in opposite directions.

Mistakes to Avoid

Converting without projecting MAGI first. You can sail over the 400% cliff and lose the whole credit, often $15,000–$25,000 for a couple.
Forgetting Social Security and muni interest count. These add to ACA MAGI, so you start closer to the cliff than your 1040 taxable income suggests.
Assuming you can undo the conversion. Recharacterizing a conversion has been banned since 2018, so an over-the-cliff conversion is permanent.
Ignoring the 2026 repayment trap. With no repayment cap for 2026, crossing the cliff means repaying every advance dollar on Form 8962.
Converting in the wrong year. A conversion counts in the calendar year you do it; do it January 1 instead of December 31 and you commit a full extra year of MAGI.
Leaving no safety margin. Stray dividends, interest, or a capital gain can push you over a target you cut too close.
Overlooking cost-sharing reductions below 250% FPL. A conversion that lifts MAGI past 250% FPL can cost you lower deductibles and copays, not just premium dollars.
Treating ACA MAGI like IRMAA MAGI. They use different add-backs and different years, so planning with the wrong one misfires.

Do’s and Don’ts

Do run a year-end MAGI projection before converting, because the cliff makes the cost jump, not glide.
Do know your exact 400% FPL line for your household size, because one dollar over erases the credit.
Do consider converting heavily in years you are already over 400% FPL, because the subsidy is already gone.
Do keep Form 1095-A and conversion records, because you need them to reconcile Form 8962.
Do check whether your state offers its own subsidy, because it may blunt the federal cliff.
Don’t convert in December without checking your year-to-date income, because surprises push you over.
Don’t assume Roth withdrawals raise MAGI, because qualified ones do not and can fund living costs subsidy-free.
Don’t overshoot your target FPL, because the conversion cannot be reversed.
Don’t ignore state income tax on the conversion, because it can dwarf the subsidy math in high-tax states.
Don’t rely on advance credits if a conversion is likely, because you may have to repay all of them.

Pros and Cons of Converting While on ACA Coverage

Pros first. Converting now locks in tax-free growth, because future Roth withdrawals add nothing to MAGI. It shrinks future RMDs, because less stays in the pretax account. It can fill a low tax bracket cheaply, because early-retiree income is often low. It removes uncertainty about future tax rates, because the tax is paid today. And in an over-the-cliff year it has no added subsidy cost, because there is no credit left to lose.

Now the cons. A conversion can wipe out a large premium credit, because it raises MAGI dollar for dollar. It is permanent, because recharacterization is banned. It can trigger full repayment of advance credits in 2026, because the repayment cap is gone. It can cost cost-sharing reductions below 250% FPL, because those phase out as income rises. And it raises state income tax in high-tax states, because the conversion is ordinary income there too.

What to Do Next

Find your household’s exact 400% FPL line for 2026 — $62,600 single or $84,600 for two in the contiguous states.
Estimate your full-year ACA MAGI, adding back Social Security and tax-exempt interest, before you convert anything.
Subtract your estimated MAGI from your cliff line to see your safe conversion headroom, then leave a few thousand dollars of margin.
Run both paths — convert vs. don’t — in a calculator that models the subsidy loss, not just the tax.
Convert by December 31 for the current tax year, in the amount that keeps you under your target.
Keep Form 1095-A and conversion records, and reconcile on Form 8962 at filing.
Call a CPA or fee-only planner if you are near the cliff, on a state marketplace, or converting a large balance — this is exactly the situation where professional modeling pays for itself.

This article is educational, not personal tax advice. A Roth conversion near the ACA cliff mixes federal credits, state tax, and timing in ways that turn on your exact numbers, so confirm your situation with a licensed CPA, tax attorney, or fee-only financial planner before you act.

FAQs

Does a Roth conversion count as income for ACA subsidies? Yes. For tax year 2026, the taxable amount of a Roth conversion is ordinary income that flows into your ACA MAGI dollar for dollar, which can lower or eliminate your premium tax credit.

Do Roth withdrawals affect ACA subsidies? No. Qualified Roth distributions (account 5+ years old, owner over 59½) are tax-free and add nothing to ACA MAGI, so they can fund living costs without shrinking your 2026 credit.

What is the 2026 ACA subsidy cliff? 400% of the federal poverty level. For 2026, that is $62,600 for one person and $84,600 for two. Above it, the federal premium tax credit drops to $0.

Does Social Security count toward ACA MAGI? Yes. Your full Social Security benefit counts toward ACA MAGI, including the portion not taxed on your 1040, which puts many retirees closer to the cliff than they expect.

Can I undo a Roth conversion that blew my subsidy? No. Recharacterizing a conversion has been banned since 2018, so a conversion that pushes you over the cliff is permanent for that tax year.

How much subsidy can I lose by crossing the cliff? Often $15,000–$25,000 for an older couple. A 62-year-old couple can lose a credit worth roughly $24,000 in 2026 by going even $1 over 400% FPL.

Is there a repayment cap if my conversion pushed me over 400% FPL in 2026? No. For tax year 2026, the repayment cap is gone, so you must repay every dollar of excess advance premium tax credit on Form 8962.

What form reports a Roth conversion? Form 8606. It tracks the taxable amount and any basis of the conversion, and the taxable figure flows to your 1040 and into your MAGI.

What form reconciles my ACA subsidy? Form 8962. You file it with your return to compare advance credits received against the credit your final MAGI allows.

Should I convert more in a year I’m already over 400% FPL? Often yes. If your MAGI is already above the cliff, you have no premium credit left to lose, so that can be your best year to convert aggressively.

Does a Roth conversion also affect Medicare IRMAA? Yes. Conversions raise the MAGI used for IRMAA, and because IRMAA looks back two years, a conversion at 63 can lift your Medicare Part B and D premiums at 65.

When is the deadline to convert for a given tax year? December 31. A Roth conversion counts in the calendar year you complete it, and unlike IRA contributions there is no extension into the following April.

Word count: approximately 3,500 words. This article reflects federal rules as of June 2026 for tax year 2026; confirm current figures before you file or convert.

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