A deferred gain is profit from selling or exchanging property that you don’t have to report as taxable income yet, because a specific provision of the Internal Revenue Code lets you postpone recognition. Postpone is the operative word. Deferral is not forgiveness, and the IRS keeps track of the untaxed profit by lowering the cost basis of whatever you acquire next. That built-in liability follows the replacement asset until you eventually sell in a taxable transaction, trigger a statutory recognition date, or die holding it.
Four Code sections do most of the work in this area for individual investors: installment sales under Section 453, like-kind exchanges of real estate under Section 1031, involuntary conversions under Section 1033, and Qualified Opportunity Fund investments under Section 1400Z-2. Each has its own trigger for when the tax finally comes due.
How the IRS Tracks a Deferred Gain
Every deferral mechanism in the Code uses the same enforcement tool: a reduced basis on the replacement property. If you defer $300,000 of gain through a 1031 exchange and buy a replacement worth $1,000,000, your basis in the new property is $700,000, not $1,000,000. The $300,000 gap is the deferred gain sitting in your records, waiting.
The math compounds across successive deferrals. Someone who completes three 1031 exchanges over 20 years might end up holding property worth $2,000,000 with a tax basis of $400,000. That $1,600,000 spread is accumulated deferred gain, and it all becomes taxable in the year the property is finally sold outside another deferral. Installment sales track the same idea differently, recognizing pieces of the gain as each payment arrives rather than in a single lump.
Recordkeeping matters here more than in almost any other corner of tax planning. If you can’t document original basis, adjustments, and gain calculations across every deferral, the IRS can presume a zero basis, and you can end up paying tax on more than you actually made.
Installment Sales: Recognition as Payments Arrive
An installment sale is any disposition of property where at least one payment is received after the close of the tax year of the sale.1Office of the Law Revision Counsel. 26 USC 453 – Installment Method Rather than recognizing the whole gain up front, you spread it across the years cash actually comes in. The taxable share of each payment equals the payment multiplied by your gross profit percentage (total gain divided by contract price).
The installment method applies automatically to sales that qualify. If you’d rather pay all the tax in the year of the sale, you can elect out, but only by the due date (including extensions) of that year’s return. Changing your mind later requires IRS consent. Installment sale income is reported on Form 6252 in the year of sale and every subsequent year a payment arrives.2Internal Revenue Service. About Form 6252, Installment Sale Income
Some sales cannot use the method at all. Dealer dispositions (regular installment sales of the same type of personal property, or real property held for sale to customers in the ordinary course of business), property that would be inventory at year-end, and sales of publicly traded stock or securities are all excluded by statute and treated as fully received in the year of sale.1Office of the Law Revision Counsel. 26 USC 453 – Installment Method
Depreciation Recapture Cannot Be Deferred
If you depreciated the property, part of the gain may not qualify for installment treatment. Under Section 453(i), any recapture income that would be ordinary income under Section 1245 or Section 1250 must be recognized in the year of sale, even if no payment has arrived yet. Only gain in excess of that recapture is spread over the payments.
Unrecaptured Section 1250 gain is a different animal. That’s the portion of gain on depreciable real property attributable to straight-line depreciation, taxed at a maximum 25% rate. Treasury regulations allow this category to ride along on the installment method with the rest of your capital gain, taken into account before the adjusted net capital gain in each payment.3eCFR. 26 CFR 1.453-12 – Allocation of Unrecaptured Section 1250 Gain Reported on the Installment Method
Interest Charges on Large Deferred Balances
Big installment deals come with an extra cost. Section 453A imposes an interest charge on the deferred tax liability when the sales price exceeds $150,000 and the face amount of installment obligations outstanding at year-end exceeds $5 million.4GovInfo. 26 USC 453A – Special Rules for Nondealers The charge applies only to the portion above $5 million, and it uses the IRS underpayment rate in effect for the last month of the tax year.5Internal Revenue Service. Interest on Deferred Tax Liability For very large sales, the interest can erode enough of the benefit that some sellers elect out of installment treatment entirely.
Like-Kind Exchanges Under Section 1031
Section 1031 is the most widely used deferral tool in real estate. It lets you exchange investment or business-use real property for other like-kind real property without recognizing gain.6Office of the Law Revision Counsel. 26 USC 1031 – Exchange of Real Property Held for Productive Use or Investment Since the Tax Cuts and Jobs Act of 2017, only real property qualifies; equipment, vehicles, artwork, and other personal property no longer do.7Internal Revenue Service. Like-Kind Exchanges – Real Estate Tax Tips
“Like-kind” reads broadly for real estate. Raw land for a commercial building, a rental condo for a warehouse, a single-family rental for an apartment complex — all fine. Both the property you give up and the property you receive have to be held for business use or investment. Property held primarily for sale to customers doesn’t qualify, and U.S. real property is not like-kind to foreign real property.
The 45-Day and 180-Day Deadlines
Two hard timelines govern every 1031 exchange. You have 45 calendar days from the transfer of the property you’re giving up to identify the replacement, and 180 calendar days (or the due date of your return with extensions, whichever comes first) to actually receive it. Miss either deadline and the entire gain becomes taxable in the year of the original sale. There is no reasonable-cause exception and no waiver.
Because it’s rare to find a buyer who happens to own the exact property you want, nearly all exchanges use a Qualified Intermediary. The QI holds the sale proceeds and arranges the purchase of the replacement, keeping you out of actual or constructive receipt of the cash. Touching the money yourself, even briefly, disqualifies the exchange.
Boot Triggers Partial Recognition
Cash or non-like-kind property received in the exchange is called “boot,” and you recognize gain up to the amount of boot you receive. Debt relief counts too. If the mortgage on the old property was $400,000 and the new mortgage is $300,000, the $100,000 reduction is boot. Full deferral requires a replacement of equal or greater value with equal or greater debt assumed.
Involuntary Conversions Under Section 1033
When property is destroyed, stolen, condemned, or disposed of under threat of condemnation, and the insurance proceeds or award exceed your basis, Section 1033 lets you defer the gain by reinvesting in replacement property that is “similar or related in service or use” to what was lost.8Office of the Law Revision Counsel. 26 USC 1033 – Involuntary Conversions
That standard is narrower than the like-kind test. You cannot replace a fire-destroyed rental with raw land and defer the gain. The replacement must serve a substantially similar function, though when both properties are real estate held for business or investment, the two tests largely overlap.9Internal Revenue Service. Involuntary Conversions – Real Estate Tax Tips
You generally have two years after the close of the first tax year in which any part of the gain is realized to buy replacement property, and the IRS can grant extensions on application. If the replacement property comes directly (rather than money), deferral is automatic. If you receive money and buy the replacement in time, you elect deferral and recognize gain only to the extent proceeds exceed what you spend.
Qualified Opportunity Fund Investments
Section 1400Z-2 works differently from the mechanisms above. Instead of exchanging one asset for another, you take a capital gain from any source and roll it into a Qualified Opportunity Fund within 180 days of the sale that produced the gain.10GovInfo. 26 USC 1400Z-2 – Special Rules for Capital Gains Invested in Opportunity Zones
The deferred gain has to be picked up as income on the earlier of the date you sell the QOF investment or December 31, 2026. That date is a hard stop and applies whether or not you’ve sold the investment or received any cash.11Internal Revenue Service. Opportunity Zones Frequently Asked Questions The amount included is the lesser of the original deferred gain or the investment’s fair market value at that date, minus your basis. The gain keeps its original short-term or long-term character.
The statute’s 10% and 15% basis step-ups (for five- and seven-year holds) are no longer reachable for new money because the recognition date is fixed at December 31, 2026. A separate benefit does survive: hold the QOF investment at least 10 years, and you can elect to adjust basis to fair market value on sale, making all appreciation inside the fund tax-free. That exclusion applies to growth within the fund, not to the originally deferred gain. Investors have to file Form 8997 each year to keep the election intact.
What Deferred Gain Costs When It Finally Hits
Deferred gain is taxed at the rates in effect for the year of recognition, not the year of the original sale. In 2026, long-term capital gains rates are 0%, 15%, or 20% depending on taxable income. Married couples filing jointly reach the 15% bracket at $98,900 of taxable income and the 20% bracket at $613,700. Single filers hit 15% at $49,450 and 20% at $545,500.
Unrecaptured Section 1250 gain on depreciated real property is capped at 25%, higher than the standard long-term rate for most taxpayers. Section 1245 recapture is taxed as ordinary income at your marginal rate, which can reach 37%.
On top of those rates, the Net Investment Income Tax adds 3.8% on capital gains, rental income, and other investment income when modified adjusted gross income exceeds $250,000 for joint filers, $200,000 for single filers, or $125,000 for married filing separately.12Internal Revenue Service. Topic No. 559, Net Investment Income Tax Those thresholds aren’t indexed for inflation. A large deferred gain recognized in a single year can push income well above them, and the extra 3.8% then applies to the whole gain. Worth factoring into any decision about when to end a deferral.
What Happens to Deferred Gain at Death
Death does very different things to deferred gain depending on which Code section produced it, and the gap is wide enough to change estate planning strategy.
1031 Exchanges: The Basis Step-Up Erases the Gain
Property acquired from a decedent takes a basis equal to its fair market value at the date of death under Section 1014.13Office of the Law Revision Counsel. 26 USC 1014 – Basis of Property Acquired From a Decedent The step-up effectively wipes out deferred gain from prior like-kind exchanges. Fifteen years of rolling exchanges producing a $1,200,000 spread between market value and basis? The heir inherits at current fair market value and can sell right away with no capital gains tax. This is what people mean by the “swap till you drop” strategy.
Installment Sales: The Deferred Tax Follows the Payments
Installment obligations don’t get the same treatment. When a seller dies with payments still owed, those amounts are income in respect of a decedent under Section 691. The estate or the person who inherits the right to the payments continues to report the same taxable portion of each payment that the decedent would have.14eCFR. 26 CFR 1.691(a)-5 – Installment Obligations Acquired From Decedent No gain is triggered by the transfer itself, but the deferred tax doesn’t disappear. Same tool, opposite outcome at death.