Rent Out My House or Sell It? You Have Three Years to Decide.

A couple takes a job three states away and lists the house. Two weeks in, the only offer is $30,000 under asking, and somebody at the new office tells them to rent it out and sell when the market turns. That is good advice for about three years and expensive after that. So, the question that lands in my inbox every time somebody relocates: should I rent out my house or sell it, and what does the renting cost in tax.

Section 121(a) tests the five years ending on the date of sale, not the day you move out. Inside that window you need 24 months of ownership and 24 months of use as your principal residence, and §121(b)(2)(A) lifts the exclusion to $500,000 on a joint return when both spouses clear the use test. The months do not have to be consecutive, and the gain is figured the same way as on any home sale.

Run the window forward and the deadline falls out of the arithmetic. Say you lived there from 2018 until June 30, 2026, then moved. Close on June 30, 2029 and the five-year window opens July 1, 2024, which still holds two full years of you living there. Close a day later and the window opens a day later, your use period comes up short of 24 months, and the exclusion is gone. There is no partial credit for 23 months. Section 121(c) prorates it only when a job change, health, or an unforeseen circumstance forces the sale, and "the market finally came back" is none of those.

Most of page one on this question warns that §121(b)(5) splits the gain between qualified and nonqualified use, so every month of rent eats a slice of the exclusion. The rule is real, and it bites hard in the other direction, where a landlord moves into a former rental and finds most of the gain taxable anyway. It does not reach your situation.

Section 121(b)(5)(C)(ii)(I) says a period of nonqualified use does not include any part of the five-year period falling after the last date you used the property as your principal residence. Rent that starts the month after you move out sits inside that exception. The allocation rule exists to stop people from buying rentals, moving in for the last two years, and excluding gain that piled up while tenants covered the mortgage. Renting on your way out the door is the fact pattern Congress left alone.

A couple bought in 2018 for $390,000, put $25,000 into a roof and a kitchen, and moved out June 30, 2026 with the house worth $720,000. Sell that day at $720,000 with 6% in selling costs and the gain is $261,800, every dollar of it excluded, federal tax of zero. Here is the same house rented for three years first and sold June 30, 2029, the last day that works.

The whole bill is $9,789, and every dollar traces back to depreciation they deducted along the way. Section 121 covered $327,600 of the gain, the tenants covered three years of carrying costs, and the house picked up $70,000. That is a rounding error, which is why I rarely talk anyone out of renting for a stretch.

Close the same sale on July 1, 2029 instead and the $327,600 stops being excluded. It becomes long-term capital gain at 15%, and the full $362,812 becomes net investment income subject to the 3.8% tax under §1411. The bill goes from $9,789 to $71,378. That is $61,589 for one day of calendar, and nothing about the house changed.

The error I fix most often on a converted home is the depreciable basis. People hand over the Zillow estimate or the appraisal from last year's refinance, and the software depreciates it without complaint. Treas. Reg. §1.168(i)-4(b) sets the depreciable basis on a conversion from personal use at the lesser of fair market value or adjusted basis at the conversion date. In a market that has gone up, which is the only reason you are reading this, adjusted basis is the lower number and it controls. In the table above that is $415,000, not $720,000.

Depreciating $720,000 would have thrown off roughly $21,000 a year instead of $12,073, and the overstatement does not stay buried. Section 1016(a)(2) reduces basis by depreciation allowed or allowable, so the excess comes back as gain at sale whether the deduction ever did you any good or not. Cheap to fix before the first rental return goes out, annoying after, and if a year of it goes missing entirely, Form 3115 catches it up on the current return. Two more items at conversion: pull the land out using the county assessor's land-to-improvement ratio, and start the clock when the house is ready and available to rent rather than when a tenant signs, on 27.5-year straight line under §168(c) with the mid-month convention of §168(d)(2).

1. 01Put the sale deadline on the calendar. Three years from the day you stopped living there, and it is the closing date that counts, not the listing date.
2. 02Fix the depreciable basis in writing now: original cost plus improvements, less the assessor's land share, compared against an appraisal or a broker price opinion from the conversion month. Keep both numbers in the file.
3. 03Check whether the rental loss is even deductible. Rental real estate is passive under §469, and the $25,000 active participation allowance phases out between $100,000 and $150,000 of modified AGI, so a two-earner household usually parks the loss on Form 8582 instead of using it.
4. 04Decide what the delay is buying. Selling inside three years makes this a cash flow decision and the tax is small. Keeping it past the deadline makes it a rental business, where the exclusion is gone and the 25% depreciation slice and a possible 1031 exchange are what you price instead.

What I would do: if you have two years of living in the house behind you and any real chance of selling inside three, rent it out. The detour costs single-digit thousands, all of it depreciation you deducted along the way. If the house is a keeper, decide that on purpose. The worst version of this is drifting past month 36 without noticing and handing back a $500,000 exclusion to save a few months of market timing.