Converting Your Primary Residence to a Rental Property
Renting out the home you used to live in is one of the most common ways people become landlords — and one of the most tax-sensitive. Two rules pull in opposite directions: the Section 121 exclusion can wipe out up to $250,000 or $500,000 of gain, but the longer you rent, the more of that exclusion you can lose. The order in which you live in and rent the home decides the outcome. Here is how it works.
Table of Contents
The Section 121 Home-Sale Exclusion
Under Internal Revenue Code Section 121, you can exclude up to $250,000 of gain on the sale of your main home ($500,000 for a married couple filing jointly, when both meet the use test, at least one meets the ownership test, and neither is barred by the frequency rule). To qualify, you must have owned and used the home as your principal residence for periods totaling at least two years during the five years ending on the date of sale — the "2-of-5" test. The two years of ownership and two years of use do not have to be continuous or the same period. (IRC §121(a), (b); IRS Publication 523.)
The two-year clock keeps running after you move out
Because the test looks back five years from the sale date, you can move out, rent the home, and still qualify for the exclusion — as long as you sell before your two years of qualifying use fall outside that five-year window. In practice that gives you roughly a three-year rental runway after you move out before the exclusion is lost entirely.
You generally can use the exclusion only once every two years (IRC §121(b)(3)). If you fail the ownership/use or frequency tests because of a change in employment, a health reason, or an unforeseen circumstance, you may still qualify for a reduced, pro-rated exclusion (IRC §121(c)).
So far, so good. But two separate rules chip away at the exclusion once a home has been a rental — and most people only learn about them at closing.
Depreciation Recapture Is Never Excluded
Gotcha #1
The Section 121 exclusion does not cover depreciation. Under IRC §121(d)(6), gain up to the amount of depreciation you claimed (or could have claimed) for periods after May 6, 1997 is not excludable — it is recognized as unrecaptured Section 1250 gain and taxed at a federal rate of up to 25%, even if the rest of your gain is fully excluded.
Every year you rent the property, you take depreciation, which lowers your basis. When you sell, that depreciation comes back as recapture first — before you get to apply the exclusion to anything. This is the same "unrecaptured §1250 gain" that applies to any rental sale, taxed at a maximum 25% federal rate (the effective rate is lower if your ordinary bracket is below 25%).
And because the recapture is based on depreciation "allowed or allowable," skipping depreciation does not help you — the IRS treats you as having taken it either way. Always claim it. For the full mechanics, see our depreciation recapture guide, and estimate the number with the Sale Tax Calculator.
Non-Qualified Use: Why the Order Matters
The second rule — IRC §121(b)(5), added for periods after 2008 — is the one that makes timing everything. Gain allocated to periods of "non-qualified use" cannot be excluded. A period of non-qualified use is any time (other than any portion before January 1, 2009) that the property is not used as the principal residence of you, your spouse, or your former spouse.
Non-excludable gain =
Total gain (after depreciation recapture)
× (periods of non-qualified use ÷ total period owned)
The statutory allocation ratio, IRC §121(b)(5)(B).
The exception that rewards "live first, rent later"
Any portion of the five-year period that is after the last date you used the home as your principal residence is not counted as non-qualified use (IRC §121(b)(5)(C)(ii)(I)). So if you live in the home first and then rent it, that later rental period generally does not reduce your exclusion. But if you rent it first and then move in, the earlier rental years are non-qualified use and shrink the exclusion pro-rata.
Two other periods are also excluded from "non-qualified use": time you were away on qualified official extended duty (military, foreign service, or intelligence — up to an aggregate of 10 years), and certain temporary absences for a change of employment, health, or unforeseen circumstances (up to an aggregate of 2 years). (IRC §121(b)(5)(C)(ii).)
Worked Example
This illustrative example applies the statutory ratio in IRC §121(b)(5)(B). Your own numbers should be run through the worksheets in IRS Publication 523.
Rent first, then move in, then sell
Result: $40,000 is taxed as unrecaptured §1250 gain (up to 25%), $120,000 is taxed as long-term capital gain, and $180,000 is excluded.
Now flip the order
If instead you had lived in the home first (2018–2023) and then rented it briefly (2024–2025) before selling in 2025, those rental years fall under the "after the last date used as a principal residence" exception (§121(b)(5)(C)(ii)(I)) — so §121(b)(5) allocates nothing to non-qualified use. The gain that was taxable in the rent-first scenario becomes excludable instead, up to your $250K/$500K cap; only the $40,000 depreciation recapture (§121(d)(6)) still applies either way. The catch: this only works if you sell within roughly three years of moving out — rent it out much longer and the sale falls outside the five-year window, you fail the 2-of-5-year use test, and you lose the exclusion entirely. Same numbers, very different tax — driven by the order of events and the timing.
Your Basis for Depreciation on Conversion
The day you convert the home to a rental is the day it is "placed in service," and you start depreciating it. Your depreciable basis is the lesser of (a) your adjusted basis on the conversion date, or (b) the property's fair market value on that date (IRS Publication 527; Treasury Reg. §1.168(i)-4(b)(1)). This special rule stops taxpayers from converting a home that has dropped in value and depreciating a paper-inflated basis.
Only the building is depreciable — land is not — so you must split the basis between land and building, and residential rental property is depreciated straight-line over 27.5 years (Publication 527). Use the Land vs Building calculator to make the split, then the Depreciation Calculator for the annual figure. Document the fair market value at conversion (an appraisal or the assessor's valuation) — you will need it years later at sale.
The Reverse Move: Rental to Residence
Some investors do the opposite — move into a rental to try to capture the Section 121 exclusion before selling. It can help, but two rules limit the payoff at the same time:
The prior rental years are non-qualified use
Here the rental period comes before the residence period, so the "after last residence use" exception does not apply. Those post-2008 rental years reduce your exclusion pro-rata under §121(b)(5).
Depreciation still recaptures
All depreciation taken after May 6, 1997 is recognized under §121(d)(6) regardless of how long you live there afterward.
If you only rent part of the home — say, a basement unit — while living in the rest, the deductions attributable to the rental portion are governed by the dwelling-unit rules of IRC §280A, and you depreciate only the rental share. See our personal-use and vacation rental guide for the mixed-use mechanics.
Conversion Checklist
Document fair market value at conversion
Get an appraisal or save the county assessment as of the conversion date — your depreciable basis is the lesser of this or your adjusted basis, and you will need the figure at sale.
Allocate basis between land and building
Only the building depreciates. Use the assessor ratio to split, and keep the record with your conversion file.
Start (and keep) depreciation
Begin 27.5-year straight-line depreciation from the placed-in-service (conversion) date. Skipping it does not avoid recapture — you will owe it either way.
Track the two-year residence clock
If you want to preserve the §121 exclusion, know the date your qualifying use falls outside the five-year look-back — roughly three years of rental after you move out.
Keep every improvement receipt
Capital improvements raise your basis and shrink your eventual gain; routine repairs are deducted currently. Records matter most at sale.
This guide is educational, not tax advice. It summarizes federal rules (IRC §121, §280A, and IRS Publications 523 and 527) as of August 2026; the $250,000/$500,000 exclusion amounts are fixed by statute and not inflation-indexed. Your result depends on your specific facts, state law, and the actual Publication 523 worksheets — confirm with a CPA or tax professional before you convert or sell.
Model Your Conversion Before You Rent
SheltrIQ tracks your basis, depreciation, and exit-tax exposure per property — so you can see the recapture and capital-gains picture before you convert your home.