What is the net investment income tax for 2026?

3.8% of the smaller of your net investment income and your modified AGI above $200,000 (single, head of household), $250,000 (married filing jointly) or $125,000 (married filing separately) (IRC §1411; IRS).

Are the NIIT thresholds adjusted for inflation?

No. The $200,000 and $250,000 amounts are written into the law with no inflation adjustment (IRC §1411(b)).

What counts as net investment income?

Interest, dividends, capital gains, rents, royalties and non-qualified annuities, less the expenses that go with them. Wages, Social Security and distributions from IRAs, 401(k)s, 403(b)s and 457(b)s are not investment income (§1411(c)).

Does an IRA withdrawal or a Roth conversion trigger the NIIT?

It is not taxed as investment income, but it raises your modified AGI. If you have investment income, more MAGI can mean more NIIT: in the example the next $10,000 of IRA withdrawal adds $380 of it.

How much NIIT will I pay on a capital gain?

3.8% of the part of the gain that falls above your threshold, as long as your investment income is larger than your MAGI excess. In the example the next $10,000 of long-term gain adds $380, on top of the capital gains tax.

How do I reduce the net investment income tax?

Lower either side of the comparison: realise less gain in the year (harvest losses, spread a sale over two years) or lower MAGI. In the example $30,000 less gain changes the NIIT by −$1,140. The calculator shows how much more gain fits under your threshold.

Net Investment Income Tax Calculator 2026

Enter your 2026 income. The federal tax engine works out whether the 3.8% net investment income tax (NIIT) applies to you, how much it is, what the next capital gain or IRA withdrawal adds to it, and how much more gain fits before it starts.

The rate on the gain itself is on 2026 capital gains tax rates. Selling at a loss to offset gains? The tax-loss harvesting calculator nets them for you.

How much net investment income tax will I pay in 2026?

The net investment income tax is 3.8% of the smaller of your net investment income and the amount by which your modified adjusted gross income is over $250,000 (married filing jointly), $200,000 (single or head of household) or $125,000 (married filing separately) (IRC §1411). The thresholds are set in the law and do not rise with inflation. Investment income is interest, dividends, capital gains, rents and royalties and non-qualified annuities; wages, Social Security and IRA or 401(k) withdrawals are not (§1411(c)). Example: a married couple, 67 and 65, with a $60,000 pension, $50,000 of Social Security, $40,000 of IRA withdrawals, $15,000 of interest, $30,000 of dividends and a $120,000 long-term gain have $307,500 of modified AGI, $57,500 over the threshold. Their $165,000 of investment income is more than that, so the tax is 3.8% of $57,500: $2,185, filed on Form 8960.

The worked example, computed by the tax engine: married filing jointly, ages 67 and 65, $60,000 pension, $50,000 Social Security, $40,000 IRA withdrawals, $15,000 interest, $30,000 dividends ($25,000 qualified), $120,000 long-term gain, 2026.
Key number	2026
Modified adjusted gross income (§1411(d))	$307,500
Over the $250,000 joint threshold (IRS)	$57,500
Net investment income (interest + dividends + gain) (§1411(c))	$165,000
Net investment income tax (3.8% of the smaller)	$2,185
Total federal tax, including it	$41,299
NIIT on the next $10,000 of long-term gain	$380
NIIT added by the next $10,000 of IRA withdrawal	$380
NIIT change with $30,000 less gain	−$1,140

The NIIT is one line of the return (Schedule 2). Your whole 2026 return, with the NIIT, the deductions, your state and what you have paid, ends in a refund or an amount owed: 2026 tax return calculator (free: your federal and state refund or amount owed) →

An estimate from QuantCalc’s open tax engine (federal 2.3.2, state 1.14.2) for the 2026 tax year. Not tax advice: your return depends on facts this page does not ask about, so check a move with your tax preparer or custodian before acting. How the engine computes each line, with its official source: federal, state.

Run your own numbers in the calculator below.

Your 2026 net investment income tax

Filing status Your age on Dec 31, 2026 Spouse’s age on Dec 31, 2026

Your 2026 income (the whole year)

Wages ($) Pension or annuity ($) Social Security ($)Gross benefits IRA / 401(k) withdrawals ($)Including RMDs Roth conversions ($) Taxable interest ($) Dividends, total ($)Box 1a of your 1099-DIVs … of which qualified ($)Box 1b Net long-term capital gains ($) Net short-term capital gains ($)

Rental income, royalties, annuities bought outside a retirement plan, foreign income and investment expenses are not asked here, so the engine counts none of them; the 2026 tax return calculator takes the whole return.

Example — enter your numbers

Does an IRA withdrawal or a Roth conversion raise the NIIT?

An IRA or 401(k) withdrawal is never investment income (IRC §1411(c)(5)), but it is part of your modified AGI. When your investment income is larger than your MAGI excess, as in the example, every extra dollar of MAGI is taxed at 3.8%: the next $10,000 of IRA withdrawal adds $380 of NIIT, the same as $10,000 of gain ($380), on top of the income tax ($2,580 of federal tax in all). The same is true of a Roth conversion. Taking $30,000 less gain this year, by harvesting a loss of that size or deferring a sale, changes the couple’s NIIT by −$1,140.

How much more gain can I take before the NIIT starts?

A single 70-year-old with $40,000 of Social Security, $60,000 of IRA withdrawals, $20,000 of qualified dividends and a $50,000 gain has $164,000 of modified AGI, under the $200,000 single threshold: no NIIT. They could take $36,000 more long-term gain in 2026 before the tax starts (the engine adds gain until the NIIT is above zero, so the Social Security it makes taxable is counted).

Common questions

What is the net investment income tax for 2026?: 3.8% of the smaller of your net investment income and your modified AGI above $200,000 (single, head of household), $250,000 (married filing jointly) or $125,000 (married filing separately) (IRC §1411; IRS).
Are the NIIT thresholds adjusted for inflation?: No. The $200,000 and $250,000 amounts are written into the law with no inflation adjustment (IRC §1411(b)).
What counts as net investment income?: Interest, dividends, capital gains, rents, royalties and non-qualified annuities, less the expenses that go with them. Wages, Social Security and distributions from IRAs, 401(k)s, 403(b)s and 457(b)s are not investment income (§1411(c)).
Does an IRA withdrawal or a Roth conversion trigger the NIIT?: It is not taxed as investment income, but it raises your modified AGI. If you have investment income, more MAGI can mean more NIIT: in the example the next $10,000 of IRA withdrawal adds $380 of it.
How much NIIT will I pay on a capital gain?: 3.8% of the part of the gain that falls above your threshold, as long as your investment income is larger than your MAGI excess. In the example the next $10,000 of long-term gain adds $380, on top of the capital gains tax.
How do I reduce the net investment income tax?: Lower either side of the comparison: realise less gain in the year (harvest losses, spread a sale over two years) or lower MAGI. In the example $30,000 less gain changes the NIIT by −$1,140. The calculator shows how much more gain fits under your threshold.