Tim Dick, CFP®
Posted on May 27, 2026
Selling a home is one of the most emotionally layered financial decisions a family can make. By the time you reach the closing table, you’ve navigated months of doubt, hope, and stress, only to be hit by a question that should have come first: What are we going to owe in taxes? Before you put the proceeds toward your next chapter, make sure you’re not caught off guard by the IRS.
Capital Assets and How They Are Taxed
Real estate is a capital asset, meaning any profit from its sale is taxed as a capital gain. Gains on assets held more than one year qualify for preferential long-term rates of 0%, 15%, or 20% depending on your overall income level. Gains on assets held one year or less are taxed as ordinary income, with rates as high as 37%. Some higher-income taxpayers may also owe an additional 3.8% Net Investment Income Tax (NIIT).
Consider a simple stock example: you buy shares for $4,000 and sell them three years later for $9,000. You owe tax on the $5,000 gain, and at a 15% long-term rate, that’s $750 at tax time.
Real estate follows the same logic at its core: buy land for $40,000, sell it for $90,000, and you have a $50,000 taxable gain with a $7,500 tax bill. But unlike stocks, real estate comes with special rules that can dramatically reduce what you owe, most notably the Section 121 exclusion and the ability to increase your cost basis through capital improvements.
The Section 121 Exclusion
The tax code offers a generous benefit to homeowners who sell their primary residence. Under Section 121, single filers can exclude up to $250,000 of capital gain from taxable income, and married couples filing jointly can exclude up to $500,000. To qualify, you must meet two tests:
- Ownership Test: You must have owned the home for at least two of the five years immediately preceding the sale.
- Use Test: You must have used the home as your primary residence for at least two of those same five years.
The two years do not need to be consecutive, and you can use this exclusion once every two years. If your gain falls within the exclusion limit and you meet both tests, you owe no federal capital gains tax on that profit, making Section 121 one of the most valuable tax breaks available to individual taxpayers.
Example: Mike and Sally bought their home in 1997 for $150,000. After their kids moved out, they decided to downsize and sold the home for $650,000. Their $500,000 gain is completely tax-free under Section 121.
When your gain exceeds the exclusion, only the amount above the limit is taxable.
Example (continued): If Mike and Sally’s home instead sold for $900,000, they would still benefit from the full exclusion, but $250,000 of gain ($900,000 minus $150,000 cost minus the $500,000 exclusion) would remain taxable at capital gains rates.
The Section 121 exclusion amounts have not been adjusted for inflation since 1997. As home values have risen significantly over the decades, the exclusion covers a smaller share of real gains for many homeowners.
It is also important to note that Section 121 applies only to your primary residence. Selling a second home or investment property does not qualify, and the full gain will be taxable.
Partial Exclusions: When Life Gets in the Way
If you are forced to sell before meeting the two-year requirement, you may still qualify for a prorated exclusion based on how long you did live there. The IRS recognizes three qualifying circumstances:
- Change in employment: You relocated for a new job or were transferred, and the new workplace is at least 50 miles farther from the home than your previous job was.
- Health reasons: You sold to obtain medical care for yourself or a family member, or to care for someone who needs assistance.
- Unforeseen circumstances: The IRS recognizes qualifying events including the death of a co-owner or spouse, divorce or legal separation, multiple births from the same pregnancy, job loss leading to an inability to cover basic living expenses, and natural disasters or acts of terrorism. Events outside this list may also qualify depending on the facts and circumstances.
Other notable exceptions:
- Surviving spouse: A surviving spouse may claim the full $500,000 exclusion if the home is sold within two years of the spouse’s death and the couple would have qualified immediately before the death.
- Military and government service: Active-duty military, Foreign Service officers, and certain intelligence employees on extended assignment can suspend the five-year clock for up to 10 years, providing significant additional flexibility to meet the use test.
- Divorce: Time that a former spouse spent living in the home may count toward the seller’s use test in certain cases, potentially preserving part of the exclusion.
Tracking Your Cost Basis: Why It Matters
Your cost basis is the starting point for calculating your gain, and getting it right can save you thousands of dollars. Your basis begins with the purchase price plus closing costs paid at acquisition, and is adjusted upward for qualifying capital improvements made over time.
What counts as a capital improvement?
The IRS distinguishes between repairs, which maintain the property’s condition and do not increase your basis, and capital improvements, which add value, extend the property’s useful life, or adapt it to a new use. Examples of improvements that increase your basis include:
- Adding a room, garage, or deck
- Replacing a roof or HVAC system
- Kitchen or bathroom remodels
- New windows or doors
- Installing a new driveway
- Permanent, substantial landscaping additions
What does not count?
Routine repairs and maintenance do not increase your basis. This includes painting, fixing a leaky faucet, and patching drywall.
Keeping thorough records is essential. Save all receipts, contracts, and permits for every improvement, organized by year and project. If you sell decades after purchase and cannot substantiate your improvements, you may lose the basis step-up and pay tax on gains you did not technically realize.
Reporting the Sale on Your Tax Return
In many cases, if your gain is fully covered by the Section 121 exclusion, you are not required to report the home sale on your federal return, though it is generally best practice to do so. You must report the sale if any of the following apply:
- You received a Form 1099-S from the title company or closing agent
- Your gain exceeds the exclusion limit and tax is owed on the difference
- You are claiming only a partial exclusion
- Any portion of the home was used for business or rental purposes
When reporting is required, you will use Form 8949 (Sales and Other Dispositions of Capital Assets) to enter the sale details including the sale price, cost basis, and dates, and claim the exclusion using code H in the adjustment column. The net taxable gain then flows to Schedule D and ultimately to Form 1040. Most tax software handles this automatically once you enter the sale information.
Final Thoughts
Real estate taxation involves some of the most nuanced rules in the tax code. Whether you are approaching the sale of a cherished family home or unwinding a long-held investment property, the difference between careful planning and an afterthought can easily amount to tens of thousands of dollars. Consult with a qualified tax advisor before listing your home to fully understand the implications and avoid surprises.
This content is provided for informational purposes only and should not be relied upon in any manner as professional advice, or an endorsement of any practices, products or services. There can be no guarantees or assurances that the views expressed here will be applicable for any particular facts or circumstances, and should not be relied upon in any manner. You should consult your own advisers as to legal, business, tax, and other related matters concerning any investment.