Section 121 exclusion

A federal tax rule letting most owners exclude up to $250,000 of capital gains ($500,000 for married couples) on the sale of a primary residence. You have to have lived there 2 of the last 5 years.

Also called primary residence exclusion · Taxes & insurance · Updated September 2026

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Part 1 of 4

Why a seller cares

It is the federal rule that lets most sellers keep the gain on their home tax-free, up to $250,000 or $500,000 for a couple, if they owned and lived in it two of the last five years. The two-year test is the one most sellers ask a tax professional about.

Part 2 of 4

A simple example

A married couple bought for $220,000, lived in the home seven years, and sell for $410,000. The $190,000 gain is under the $500,000 limit.

Section 121 exclusion: a simple example
The situationHow the exclusion commonly applies
Lived in it two of the last five yearsUp to $250,000 excluded, $500,000 for a couple filing jointly
Lived in it eighteen months, moved for a jobOften a partial exclusion, prorated
A rental for the last four yearsNo exclusion; the two-year test is not met

Two years of living there, out of the last five, is what most of the rule turns on.

Part 3 of 4

What people get wrong

That it is once in a lifetime. It can be used again after two years, which is a change from the old rule people still repeat.

Part 4 of 4 · where to read next

Where it appears in the sale

What a definition is, and what it isn't

Keighbor is a software company, not a law firm, brokerage, or tax adviser. This is general information, not legal, tax, financial, or real estate advice about your sale. Your situation may differ. Before acting on a contract, disclosure, title, tax, or pricing question, ask an appropriately licensed professional in your state.

Written and researched by Keighbor Research · read against IRS Publication 523: selling your home · how we research and check what we publish

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