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Sell a rental that has doubled in value and the tax bill can sting: federal capital-gains tax, plus any depreciation recapture, plus New York State and (in the city) New York City income tax on the gain. Section 1031 of the Internal Revenue Code offers a way to keep that money working instead of handing a slice to the government today — you roll the proceeds from one investment property into another and defer the tax. Not erase it; defer it. The catch is that 1031 is unforgiving about process. Miss a deadline by a day, touch the cash at the wrong moment, or pick the wrong kind of property, and the whole thing collapses into a taxable sale.
Here's how it actually works, in plain terms.
As of June 2026. Tax law changes and the details below come from current IRS guidance; confirm specifics against the IRS before you act.
What a 1031 exchange is — and isn't
A 1031 exchange (also called a "like-kind exchange") lets you swap one piece of real property held for business or investment for another, and defer the capital-gains tax you'd otherwise owe on the sale. Since the Tax Cuts and Jobs Act of 2017, Section 1031 applies only to real property — for 2018 and later years, exchanges of personal or intangible property (equipment, vehicles, artwork, intellectual property) no longer qualify.
Two limits matter most for our readers:
- Your home doesn't qualify. A primary residence is personal-use property, not property "held for productive use in a trade or business or for investment." It cannot be the relinquished or the replacement property in a 1031 exchange. (Selling your main home has its own, separate tax break — the Section 121 exclusion, which can shelter up to $250,000 of gain for a single filer or $500,000 for a married couple filing jointly, if you meet the ownership and use tests.)
- Property you flip doesn't qualify either. Real property "held primarily for sale" — a fix-and-flip you never intended to keep — is excluded too.
"Like-kind" is broader than people expect. The IRS treats most U.S. real estate as like-kind to other U.S. real estate regardless of grade or quality. You can exchange a Brooklyn apartment building for raw land in Texas, or a strip mall for a warehouse. One firm line: U.S. real property is not like-kind to real property outside the United States.
The qualified intermediary: you can't touch the money
The single most common way people blow a 1031 exchange is by taking the cash. If you have actual or constructive receipt of the sale proceeds — even for a moment, even in your own escrow — the IRS treats it as a sale, and the deferral is gone.
The fix is a qualified intermediary (QI), an independent third party who is not your agent, attorney, or accountant. The QI holds the proceeds from the sale of your old (relinquished) property and uses them to acquire the new (replacement) property on your behalf. You sign an exchange agreement with the QI before the sale closes. Choosing a reputable, bonded QI matters — they will hold a large sum of your money, and the industry is lightly regulated.
The two clocks: 45 days and 180 days
This is where most exchanges live or die. Both clocks start on the same day — the date you transfer (close on the sale of) your relinquished property — and they run concurrently, not back to back.
| Deadline | What you must do | When |
|---|---|---|
| 45-day identification | Identify replacement property in writing, signed and delivered to the QI (or another party to the exchange) | No later than 45 days after you transfer the relinquished property |
| 180-day exchange | Actually receive (close on) the replacement property | The earlier of 180 days after the transfer, or your tax-return due date (including extensions) for that year |
Two things people miss:
- The 45 days are inside the 180, not added to it. If you identify on day 44, you still have until day 180 to close.
- The 180-day window can be cut short. It ends on the earlier of 180 days or your return's due date. So a sale late in the year can shorten the back end unless you file for an extension. Plan around it.
There are no extensions for hardship — only the limited, federally declared-disaster relief the IRS publishes from time to time. The deadlines fall on calendar days, including weekends and holidays.
Identifying replacement property: the rules of three
Within those 45 days, the identification must be specific and in writing — a legal description, street address, or distinguishable name, not "a building in Queens." You can name more than one candidate, but you must fit one of these IRS rules:
- Three-property rule: identify up to three properties, of any value. Most exchanges use this.
- 200% rule: identify any number of properties, as long as their combined fair market value doesn't exceed 200% of the value of what you sold.
- 95% rule: identify more than that, but only if you actually acquire at least 95% (by value) of everything you identified. Rarely used, and risky.
"Boot": the part that stays taxable
A 1031 exchange defers tax only on the value you roll forward. Anything you pull out is called boot, and boot is taxable in the year of the exchange.
Boot comes in two common flavors:
- Cash boot — leftover proceeds you don't reinvest. Buy cheaper than you sold, and the difference is taxable.
- Mortgage boot — a drop in debt. If your new property carries a smaller mortgage than the old one, that reduction is treated as boot, even if no cash changes hands.
The clean way to defer the entire gain: buy replacement property of equal or greater value, reinvest all the net proceeds, and carry equal or greater debt. Fall short on any of those and you'll owe tax on the shortfall.
A quick walk-through
- You decide to sell a rental and engage a QI before closing.
- The relinquished property closes; the QI holds the proceeds. Both clocks start.
- Within 45 days, you deliver a signed, written identification of your replacement property to the QI.
- Within 180 days (or your return due date, if earlier), the QI uses the funds to close on the replacement property in your name.
- You report the exchange to the IRS on Form 8824 for that tax year.
One more trap: if you exchange with a related party, special rules apply — generally, if either side disposes of the property within two years, the deferred gain comes back into income.
Why investors care — and one caveat
Done repeatedly, 1031 exchanges let an investor trade up over a career — a duplex into a small building, a building into a larger one — without the tax drag of selling at each step. The deferred gain follows you, and under current law a step-up in basis at death can reset it for heirs. That is real, lasting power, which is also why 1031 is periodically debated in Washington.
The caveat: this is a deferral, not a deduction. The tax doesn't vanish; it waits in the basis of the next property until you sell without exchanging again.
If you're weighing a 1031 exchange on a New York investment property and want to talk through timing, contact our team — and explore current listings when you're ready to identify a replacement.
Disclaimer. This article is general educational information, not legal, tax, or financial advice. 1031 exchanges are technical and the rules change. Before acting, consult a licensed tax professional or attorney and a qualified intermediary, and verify the current rules with the IRS. Figures and deadlines reflect IRS guidance as of June 2026.
Sources
- IRS — Like-kind exchanges: Real estate tax tips
- IRS — Instructions for Form 8824 (Like-Kind Exchanges)
- IRS — Like-Kind Exchanges Under IRC Section 1031 (Fact Sheet FS-2008-18)
- IRS — Topic no. 701, Sale of your home (Section 121 exclusion)
- Treasury Regulation — 26 CFR § 1.1031(k)-1, Treatment of deferred exchanges
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