Section 121 of the tax code is the reason most people who sell a house they've lived in for years never think about capital gains tax at all. It lets a qualifying seller exclude a set amount of gain from federal tax, $250,000 for a single filer, $500,000 for a married couple filing jointly, and it can be used repeatedly over a lifetime, not just once, as long as the eligibility rules are met each time.
The Ownership and Use Tests
To qualify, a seller must have owned the home and used it as their primary residence for at least 24 months out of the 60 months immediately before the sale. Those 24 months don't need to be consecutive, and a seller doesn't need to be living in the home at the moment of sale, only to have accumulated the required time within the five-year lookback window. A Tigard owner who lived in a house for three years, moved out for work eighteen months ago, and sells now still clears both tests comfortably.
How the Married-Couple Amount Actually Works
The $500,000 exclusion for a married couple filing jointly requires that at least one spouse meet the ownership test and both spouses meet the use test, and that the couple file a joint return for the year of sale. A couple where one spouse owned the home individually before marriage but both lived in it together for the required period can still typically claim the full $500,000, which surprises some sellers who assume both names need to have been on the deed the whole time.
What Happens to Gain Above the Limit
Any gain exceeding the applicable exclusion amount is taxed as a standard long-term capital gain, at federal rates of 0, 15, or 20 percent depending on income, and separately at Oregon's ordinary income rates up to roughly 9.9 percent, since Oregon has no version of Section 121 that extends beyond the federal exclusion amount. A Wilsonville couple with a $650,000 gain would exclude $500,000 and pay federal and state tax on the remaining $150,000, a materially different bill than paying tax on the full amount but still not zero.
How Often the Exclusion Can Be Used
Section 121 can generally be claimed once every two years, meaning a seller can't exclude gain on two different home sales inside a 24-month window, but there's no lifetime cap on how many times it can be used across a person's life, as long as each sale meets the ownership and use requirements independently. This is different from a one-time-use rule some older sellers remember from a previous version of the law, which no longer applies.
When the Exclusion Doesn't Cover the Whole Picture
If part of the home was used as a rental, or depreciation was claimed on any portion of it, that share of the gain is generally excluded from Section 121 treatment and taxed separately, including any applicable recapture. Sellers with a mixed-use property, or anyone unsure whether partial business use disqualifies part of the gain, are better served running the numbers with a tax advisor before listing than assuming the full exclusion applies cleanly.
Documentation That Supports the Exclusion Claim
Sellers claiming Section 121 should keep records establishing the residency timeline, such as utility bills, voter registration, or driver's license address changes, since the IRS can request evidence supporting the ownership and use tests if a return is questioned. A Canby or Sherwood seller who worked remotely and split time between two properties during the ownership period should be especially careful to document which address actually served as the primary residence during the years being claimed.
Common 1031 Exchange Questions
How much can I exclude under Section 121?
Up to $250,000 for a single filer, or $500,000 for a married couple filing jointly, provided the ownership and use tests are met for the property being sold.
Can I use the Section 121 exclusion more than once in my life?
Yes, there's no lifetime limit on how many times it can be claimed, but generally not more than once every two years, and each sale must independently meet the ownership and use requirements.
Does the 24-month residency requirement need to be continuous?
No. The 24 months can be accumulated in separate stretches within the five years before the sale, as long as the total adds up to at least two years.
What happens to gain above the exclusion limit in Oregon?
It's taxed as a standard long-term capital gain federally and as ordinary income by Oregon, since Oregon offers no separate exclusion or reduced rate beyond the federal Section 121 amount.
Does the exclusion cover a home that was partly rented out?
Generally not the portion of gain attributable to the rental use or to depreciation claimed during that period. That share is typically taxed separately, which makes mixed-use properties worth reviewing with a tax advisor before sale.
