Does a Roth conversion increase capital gains tax?

It can. The 0% and 15% capital-gains bands are measured against total taxable income with ordinary income counted first. For 2026, married couples filing jointly pay 0% on gains up to $98,900 of taxable income and 15% up to $613,700, so conversion income can push gains from 0% to 15% or from 15% to 20%.

Is a Roth conversion subject to the 3.8% net investment income tax?

The conversion itself isn't net investment income, because IRA and Roth IRA distributions are excluded. It does raise modified adjusted gross income, so it can expose more of your gains, dividends and interest to the 3.8% tax once MAGI is over $250,000 for joint filers or $200,000 for single filers.

Should I do a Roth conversion in the same year I sell property at a large gain?

It depends on where the gain falls. If the conversion would push a large gain out of the 0% band or into the net investment income tax, converting in a different year is usually cheaper. If your ordinary income already fills the 0% band and all your investment income is already subject to the 3.8% tax, the gain doesn't change the conversion's cost until taxable income nears $613,700 for joint filers.

Roth Conversion and Capital Gains in the Same Year: How They Stack in 2026

Q: Does a capital gain push a Roth conversion into a higher tax bracket?

No. Ordinary brackets apply only to ordinary taxable income, which includes the conversion. Long-term gains and qualified dividends are stacked on top and taxed at 0%, 15% or 20%, so a long-term gain doesn't change the bracket your converted dollars fall in. Short-term gains are taxed as ordinary income and do use bracket space.

Davis Oliver

10 minutes ago

8 min read

A Roth conversion and a large capital gain in the same year don't push each other into a higher ordinary tax bracket, but the conversion can raise the tax on the gain. Federal tax stacks ordinary income first, including every converted dollar, and taxes long-term gains and qualified dividends on top at 0%, 15% or 20%. So a conversion can lift gains out of the 0% band, move them toward the 20% line, and pull more of them into the 3.8% net investment income tax. This guide from the TaxesSaved CPA team, part of our retirement tax planning work for households with $1 million or more in IRAs and 401(k)s, shows the 2026 lines and two worked examples.

Does a capital gain push a Roth conversion into a higher tax bracket?

No. A long-term capital gain doesn't raise the ordinary bracket your conversion is taxed in. The ordinary brackets (10% through 37%) apply to ordinary taxable income only: wages, pensions, IRA distributions and Roth conversions, less deductions. Long-term gains and qualified dividends sit on top of that stack and are taxed at their own rates (IRS Topic 409; IRS Topic 404).

A married couple with $230,000 of ordinary taxable income in 2026 is in the 24% bracket, which runs from $211,400 to $403,550 (IRS Rev. Proc. 2025-32). A $300,000 stock gain doesn't change that: their next converted dollar is still taxed at 24%. Short-term gains are the exception. Gains on assets held one year or less are taxed as ordinary income, so they do use up bracket space.

How does a Roth conversion raise the tax on capital gains?

A conversion raises the tax on gains by filling the space below the capital-gains thresholds with ordinary income. The 0% and 15% capital-gains bands are measured against total taxable income, ordinary income first. Every converted dollar takes up room that gains would otherwise have used at a lower rate.

Illustration: a married couple, both under 65, has $40,000 of pension and interest income and $80,000 of long-term gains and qualified dividends. After the $32,200 standard deduction, their taxable income is $87,800, under the $98,900 top of the 0% band, so the full $80,000 of gains is taxed at 0% and their federal tax is $780. If they convert $100,000, ordinary taxable income becomes $107,800 and pushes all $80,000 of gains into the 15% band. The conversion adds $12,360 of tax on itself and $12,000 of tax on the gains: $24,360 in all, or 24.4% on a conversion that sat in the 10%, 12% and 22% brackets.

What are the 2026 capital gains thresholds?

For 2026, long-term gains and qualified dividends are taxed at 0% up to $98,900 of total taxable income for married couples filing jointly and $49,450 for single filers, at 15% up to $613,700 and $545,500, and at 20% above that (IRS Rev. Proc. 2025-32, section 4.03).

Filing status	0% up to	15% up to	20% above
Married filing jointly	$98,900	$613,700	$613,700
Single	$49,450	$545,500	$545,500
Head of household	$66,200	$579,600	$579,600
Married filing separately	$49,450	$306,850	$306,850

Two exceptions run higher: gains on collectibles such as coins or art are taxed at up to 28%, and the unrecaptured section 1250 part of a gain on depreciated real estate at up to 25% (IRS Topic 409).

Does a Roth conversion trigger the 3.8% net investment income tax?

A conversion isn't net investment income, but it can make more of your gains and dividends subject to the 3.8% tax. The net investment income tax (NIIT) is 3.8% of the smaller of two numbers: your net investment income, or the amount your modified adjusted gross income (MAGI) exceeds $250,000 for married couples filing jointly, $200,000 for single filers and heads of household, or $125,000 for married filing separately (IRS Topic 559).

Distributions from IRAs and Roth IRAs (sections 408 and 408A) are excluded from net investment income (IRS NIIT questions and answers, Q9). For most people MAGI for the NIIT is the same as adjusted gross income (IRS Topic 559), and a conversion is part of AGI. So the conversion raises the second number. Once MAGI is far enough over the threshold that all of your investment income is already exposed, more conversion adds no NIIT. The thresholds aren't indexed for inflation, so they catch more households each year.

What does a one-time land sale do to a $150,000 conversion?

In this composite example, a land sale raised the cost of a planned $150,000 conversion from 18.1% to 28.0%. A married couple, both about 60, has $60,000 of pension income, $10,000 of qualified dividends, and the standard deduction. They planned to convert $150,000 this year. Then family land held in a trust sold for a long-term gain of about $400,000, and the trust's lawyer confirmed the gain would be reported on the couple's own return.

2026, married filing jointly	No land sale	With $400,000 land gain
Ordinary tax added by the $150,000 conversion	$25,700	$25,700
Gains pushed from 0% to 15%	$10,000 ($1,500 of tax)	$71,100 ($10,665 of tax)
NIIT added by the conversion	$0 (MAGI $220,000)	$5,700 (MAGI $470,000 → $620,000)
Total tax added by the conversion	$27,200	$42,065
Cost per converted dollar	18.1%	28.0%

The ordinary tax on the conversion is identical in both columns: the gain didn't move the conversion into a higher bracket. The extra $14,865 comes from the gain itself, which the conversion pushed out of the 0% band and further into the NIIT. Total taxable income with the sale and conversion is $587,800, still under the $613,700 line, so none of the gain reaches 20%.

Three moves change the math. If the buyer pays over time, an installment sale reports only the part of the gain received each year, though gain on publicly traded stock can't use the installment method and any depreciation recapture is reported in the year of sale (IRS Topic 705). Losses harvested elsewhere in the portfolio offset the gain directly. Or the couple can hold the $150,000 conversion for a year without the sale, when the same conversion costs about 18%. The step that comes before any of these is confirming the gain figure itself with the trust's lawyer or preparer, because every number above moves with it.

Should a couple with large gains add $100,000 to fill the 24% bracket?

Yes, in this composite example the next $100,000 costs exactly 24%, and the gains add nothing to it. A married couple, both in their early 60s, with between $3 million and $5 million in tax-deferred accounts, has already converted $250,000 this year. They also have $60,000 of other ordinary income, $25,000 of qualified dividends, $160,000 of net long-term gains and $80,000 of itemized deductions. Their ordinary taxable income is $230,000, in the 24% bracket.

Capital-gains rate: their ordinary income already fills the 0% band, and total taxable income stays under $613,700 until the conversion passes $198,700, so all $185,000 of gains and dividends stay at 15%.
NIIT: MAGI is $495,000 before the extra conversion, $245,000 over the threshold and more than their $185,000 of investment income, so the full $185,000 is already subject to the 3.8% tax. More conversion adds none.
Bracket room: the 24% bracket ends at $403,550 of ordinary taxable income, which leaves $173,550 of room. Converting all of it adds $41,652 of tax, again 24.0%.
Past the bracket: converting $220,000 instead puts the last $46,450 in the 32% bracket and moves $21,300 of gains from 15% to 20%. That slice costs $15,929, or 34.3%.

For this household the stopping point is the top of the 24% bracket, and the gains don't move it. That's the usual result when ordinary income is already large: the gains have no 0% room left to lose, and the NIIT is already maxed out. Gains change the answer most for households with low ordinary income, like the illustration above.

How do a big gain and a Roth conversion affect Medicare IRMAA?

Both count. Social Security sets Medicare IRMAA surcharges from MAGI two years earlier, and that MAGI includes capital gains and conversions alike (SSA, MAGI definition), so 2026 income sets 2028 premiums once you are 63 or older. For married couples filing jointly, the 2026 standard premium applies at MAGI up to $218,000 and the top tier starts at $750,000 (SSA POMS HI 01101.020).

A large gain can also make the conversion's IRMAA cost zero. Had the land-sale couple above been 63, the sale alone would have put MAGI at $470,000, in Tier 4 (over $410,000 and under $750,000). The $150,000 conversion takes MAGI to $620,000, still in Tier 4, so it adds no further surcharge. In a sale year, the premium cost is set by the sale, not the conversion. The Tier 4 surcharge itself is $12,710.40 a year for a couple with Part B and Part D. More on sizing around the tiers is in Roth Conversion and IRMAA: Stop at the Tier or the Tax Bracket?.

Should you convert in the year of a big gain or wait?

Convert in the gain year when your ordinary income already uses up the 0% band and your investment income is already fully exposed to the NIIT; wait when the conversion would drag a large gain out of 0% or into the NIIT. The two worked examples show both sides.

Gains at 0% today: every converted dollar costs its bracket rate plus up to 15% on the gains it displaces. Converting in a year without the gain is usually cheaper.
Gains already at 15% and the NIIT already applying to all investment income: the gains don't change the conversion's price until total taxable income passes $613,700 (married filing jointly).
Near $613,700 of taxable income: the last slice of conversion pays its bracket rate plus 5% on each dollar of gain it moves from 15% to 20%.
Capital losses: net losses offset gains first, then up to $3,000 of ordinary income a year ($1,500 married filing separately), with the rest carried forward (IRS Topic 409).

What should you confirm before December 31?

Confirm the gain figure, the year's other income and the conversions already done before you submit the next one. A conversion has to be completed by December 31 to count for 2026.

The realized gain to date from your broker, plus any sale still to close this year, and whether a trust or partnership reports it to you on a K-1.
Mutual fund capital-gain distributions, which many funds pay late in the year.
Every conversion and IRA distribution already taken this year.
Itemized deductions or the standard deduction, and whether either spouse turns 65.
The fourth-quarter estimated tax payment due January 15, 2027.

The year-end steps for conversions are in Roth Conversion Deadline 2026: What to Do Before December 31.

How TaxesSaved sizes a Roth conversion around capital gains

These examples come from questions clients brought to TaxesSaved planning meetings this fall: a couple partway through a multi-year plan asking whether to add about $100,000 to fill the 24% bracket in a year with large gains and dividends, and a family with a one-time land sale in the same year as planned conversions. The TaxesSaved CPA team, with Big Four backgrounds, answers both inside a written multi-year Roth conversion plan that prices each year's conversion against the brackets, the capital-gains lines, the NIIT and IRMAA, puts the plan in place, and prepares the returns that report it, for clients in all 50 states.

For more real situations, read Roth Conversion Case Studies: 6 Real Retirement Tax Plans From 2026 and Before a Large Roth Conversion: 10 Questions Our Clients Ask.

To see what your IRA or 401(k) could cost you in lifetime taxes, run the free Retirement Tax Calculator.

Examples are composites built from questions raised in TaxesSaved planning meetings in 2026. Ages, balances, income and other details are changed and rounded, and no example describes a single household. Figures are federal only, use IRS Revenue Procedure 2025-32, IRS guidance on the net investment income tax, and SSA's 2026 IRMAA tables, and assume no other income changes, as of November 6, 2026. Congress can change any of this. This article is for education only and isn't tax, legal or investment advice. Tax rules change and every situation is different, so talk with a qualified tax professional before you act.