Former Home Turned Rental: Section 121 Exclusion vs a 1031

The exclusion lives about three years past your move-out date, and then it is simply gone

§121(a) excludes gain if, during the five-year period ending on the sale date, the property was owned and used as your principal residence for periods aggregating two years or more. Nothing requires it to be your residence when you sell.

So a house you left in June 2024 still carries a full exclusion on a sale through roughly June 2027, because two residence years remain inside the five-year lookback. On a sale in late 2027 the lookback contains fewer than two residence years and the exclusion disappears entirely — there is no sliding scale unless the sale is caused by a change of employment, health or an unforeseen circumstance under §121(c).

That single date drives the whole decision. Put it on the calendar before you talk to an agent, because a 60-day escrow can move a closing across it.

You do not have to choose: Rev. Proc. 2005-14 runs §121 first and §1031 on what is left

Rev. Proc. 2005-14 exists precisely for this transaction, and its section 4.02(1) is one sentence: "Section 121 must be applied to gain realized before applying §1031."

Three consequences follow. Gain attributable to depreciation is ineligible for the exclusion under §121(d)(6), but section 4.02(2) confirms §1031 can defer it. Cash boot is taken into account "only to the extent the boot exceeds the gain excluded under §121," so a modest cash pull-out can be free. And section 4.03 adds the excluded gain to the basis of the replacement property, which is why the deferral is smaller than the arithmetic first suggests.

The revenue procedure applies only if the property also satisfies the held-for-investment requirement at the time of the exchange, so the rental period has to be genuine.

Worked example: $610,000 of gain, $500,000 excluded, $110,000 deferred, and $20,000 of cash that costs nothing

Hypothetical, round numbers. A married couple buys a house in 2019 for $400,000, lives in it until mid-2024, then rents it and claims $30,000 of depreciation. In 2026 they exchange it for $20,000 of cash and a $960,000 rental. Amount realized is $980,000 against a $370,000 adjusted basis, so realized gain is $610,000.

Section 121 goes first and excludes $500,000. The remaining $110,000, including the $30,000 of depreciation gain, is deferred under §1031. The $20,000 of cash is not taxed, because it does not exceed the excluded gain. Basis in the replacement is $370,000 plus $500,000 less $20,000, or $850,000, leaving exactly $110,000 of gain riding inside a $960,000 building.

The comparison case is a plain sale at the same price: the same $500,000 is excluded, $80,000 of long-term gain and $30,000 of unrecaptured §1250 gain are taxed, and the couple walks away with cash. Whether the roughly twenty thousand dollars of federal tax that the exchange defers is worth committing $960,000 to real estate is the actual question, and it is one to model with your CPA.

Renting it out after you leave does not shrink the exclusion, which is the opposite of what most owners assume

Nonqualified use under §121(b)(5) taxes the share of gain matching the periods after 2008 when the property was not your principal residence, but the statute carves out the stretch of the five-year lookback that comes after the last day you lived there.

That carve-out is the whole reason this plan works. Years as a landlord at the end of your ownership do not enter the fraction, so a house you occupied for eight years and rented for two gives you the full exclusion, not eighty percent of it.

The fraction bites in the mirror-image case: a property you rented first and moved into later. If you are contemplating that direction instead, the arithmetic is on our page about exchanging into a future home.

Depreciation is the one slice §121 never touches, and it decides how much the exchange is worth

Every year of rental use produced a depreciation deduction whether or not you claimed it, and Publication 523 is blunt that gain equal to post-May 6, 1997 depreciation adjustments cannot be excluded and is reported under §1250.

For an accidental landlord of two or three years that slice is small, which is why a straight sale inside the window is usually the simpler answer. For someone who rented the old house for eight years, depreciation alone can run past $100,000 and a 25% rate on it is the first reason to consider the exchange.

Depreciation you never deducted still reduces basis, so an owner who filed no Schedule E during the rental years should get that corrected before the closing rather than after.

A decision rule: compare the gain to the exclusion, then compare the exclusion to another year of rent

Run the same four lines with your own numbers and have your CPA or attorney confirm them, because state tax, filing status and the depreciation history move the result.

• Gain below the exclusion and no appetite to stay a landlord: sell inside the window, exclude everything but depreciation, and skip the intermediary entirely.
• Gain far above the exclusion: sell inside the window and do both. This is the single most valuable moment in the property's tax life, and it does not come back.
• Window already closed: §1031 is what is left, and the question becomes which replacement, not which statute.
• Window closing but the property is performing: price the exclusion before you let it lapse. For a couple at a 20% capital-gains rate plus the 3.8% net investment income tax, a full $500,000 exclusion is worth about $119,000 of federal tax, which is a lot of rent.

Two timing rules and one reporting line that quietly cancel the plan

§121(b)(3) allows the exclusion only once in any two-year period, so a couple who excluded gain on a different home last year cannot use it again on this one. And if this house itself was acquired in a prior exchange, §121(d)(10) blocks the exclusion for five years from that acquisition date.

The reporting is straightforward once you know where it goes: the Instructions for Form 8824 tell you to enter the excluded amount on line 19 with the notation "Section 121 exclusion," and ordinary income recapture, if any, shows on line 21 and carries to Form 4797.

Everything else follows the normal sequence — intermediary engaged before closing, identification by day 45, purchase by day 180 — described on our page about the critical deadlines.