NYC Capital Gains Tax: What Actually Reduces a Co-op Sale

The tax code simply doesn’t ask about up to half a million dollars of gain.

What the Section 121 exclusion NYC sellers use actually excludes

Section 121 of the federal tax code lets a homeowner exclude up to $250,000 of gain from a home sale, $500,000 if married filing jointly. You must have owned and used the property as your primary residence for at least 24 of the 60 months before the sale. Those two years don’t have to be continuous. They can fall in different windows within the five-year lookback.

IRS Publication 523 states plainly that eligible property includes “a house, condo, co-op, mobile home, houseboat, or trailer.” For cooperative housing corporation stock specifically, the same publication says your basis includes “the value of the corporation stock you purchased.” The use test applies to “the house or apartment which the taxpayer was entitled to occupy as such stockholder.”

That’s the exact co-op-specific language most guides on this topic skip past. That’s why a co-op sale qualifies the same way a condo or a house does, not by inference, but by name.

You can’t claim the exclusion twice within a two-year span. If you’re married filing jointly, both spouses must independently meet the use test, even if only one spouse is on the deed or the shares.

How cost basis co-op apartment math actually works

The receipts you kept without knowing why matter here. Your cost basis starts with your purchase price. Then add your original closing costs and any capital improvements you made along the way: a renovated kitchen, a new HVAC system, a combined bathroom. A $500,000 purchase with $50,000 in closing costs and $40,000 in capital improvements gives you a basis of $590,000, not $500,000.

That distinction matters, because a common mix-up is treating those costs as a deduction. They’re not. Instead, they add to your basis, which lowers your taxable gain when you sell, a materially different mechanism than a deduction against income.

The same distinction applies to a capital-type special assessment your co-op charges. Our special assessment guide covers that in more depth.

The New York real estate transfer tax, and what NYC and NY State each take

Two governments, two bills, one closing. Once you know your taxable gain after Section 121, federal long-term capital gains rates apply first: 0%, 15%, or 20%, depending on your income bracket.

New York doesn’t have a separate capital-gains rate at all. The state taxes your gain as ordinary income, 4% to 10.9% depending on your bracket. NYC adds its own 3.078% to 3.876% on top of that for city residents.

Transfer taxes are a separate line entirely, paid at closing rather than on your tax return. NYC’s Real Property Transfer Tax runs 1% up to $500,000 and 1.425% above that for a co-op sale. New York State’s own real estate transfer tax adds 0.4% of the gross sale price on top of that.

A co-op sale also triggers the state’s Stock Transfer Tax, a flat $0.05 per share for sales at $20 or more a share. That’s because you’re technically transferring shares rather than real property.

If the buyer’s purchase price exceeds $1 million, they’ll owe the NYC Mansion Tax separately. It’s progressive since 2019, starting at 1% and rising to 3.9% at $25 million and above. That’s the buyer’s cost, not yours.

It’s worth knowing since it can affect what a buyer is willing to offer. Run your own numbers with NestApple’s closing costs calculator before assuming a sale price nets what you expect.

The net investment income tax NYC sellers forget

The 3.8% nobody budgets for until it shows up. The Net Investment Income Tax applies to investment income, including capital gains. It kicks in once your modified adjusted gross income crosses $200,000 single, or $250,000 married filing jointly.

It applies to whatever gain survives after your Section 121 exclusion, not your full sale price. That’s easy to miss if you’ve only budgeted for the exclusion and the ordinary capital-gains brackets.

Take a seller who clears $600,000 of gain on a co-op and excludes $500,000 under Section 121 as a married couple. If they cross the NIIT income threshold that year, they owe the 3.8% surtax on the remaining $100,000. That’s on top of the federal and state tax already due.

Talk to your accountant before you sign a contract, not after. The exclusion, the NIIT threshold, and your other income that year all interact.

If you’re weighing whether to buy again after this sale, our co-op costs and rules hub covers every recurring cost beyond the mortgage. That includes flip tax, tax abatements, and the rest. If you’re selling and buying with NestApple, our buyer rebate can offset part of the cost of your next purchase.

Common questions

Does Section 121 apply to co-op sales in NYC? Yes. IRS Publication 523 explicitly names cooperative housing corporation stock as eligible property, with its own basis and use-test language for co-op shareholders specifically.

How much capital gains tax exclusion do I get when I sell a co-op? Up to $250,000 for a single filer, $500,000 for married filing jointly. You must have owned and used it as your primary residence for at least two of the last five years.

Are special assessments tax-deductible when I sell? Capital-type assessments aren’t a deduction. They’re added to your cost basis, which reduces your taxable gain when you sell.

Does New York have its own capital gains tax rate? No. New York taxes capital gains as ordinary income, 4% to 10.9% at the state level, plus 3.078% to 3.876% for NYC residents.

What’s the Net Investment Income Tax and does it apply to me? A 3.8% federal surtax on investment income once your income crosses $200,000 for single filers or $250,000 for married filing jointly. It applies to any gain left after your Section 121 exclusion.

Written by Nicole Fishman Benoliel

Co-founder of NestApple and a lawyer admitted to the New York bar, not currently practising.