Do you pay capital gains tax when you sell a home in Denver?

According to Colorado real estate broker Nick Ahrens, most Denver sellers owe nothing, because the federal exclusion erases $250,000 of gain for a single filer and $500,000 for a married couple filing jointly if you owned and lived in the home two of the last five years. The tax applies to your gain, not your sale price, and your mortgage payoff never enters the math. Where Denver sellers get caught is long tenure with a single filer, a house that was ever rented, or a seller who already moved out of state. Above the exclusion, you owe federal capital gains at 0%, 15%, or 20%, plus Colorado's flat 4.4%.

By Nick Ahrens | July 21, 2026

Nick Ahrens, a Colorado real estate broker with The Apollo Group at eXp Realty, hears this question earlier in the conversation every year — usually somewhere around the third sentence, before anyone has mentioned a list price. It is the single fastest-growing seller question in the Denver metro right now, and the reason is arithmetic.

The federal exclusion has been frozen at $250,000 and $500,000 since 1997. Denver home prices have not been frozen at anything. The Case-Shiller index for Denver sat at 121.81 in February 2012 and reached 313.02 in March 2026 — roughly a 157% run in fourteen years.

So the two numbers finally collided. A Denver homeowner who bought at the bottom and stayed put is now sitting on a gain the 1997 Congress never imagined.

Here is the part most people get backwards: the tax is not on what your house sells for. It is on your gain — sale price minus what you put into the house. And nobody at the closing table cares what you still owe the bank. Your mortgage payoff has nothing to do with your gain. I have watched sellers talk themselves out of listing because they confused a $480,000 loan balance with a $480,000 tax problem.

Five steps to run your own number

This takes about twenty minutes with a folder of old receipts. Do it before you list, not after you are under contract.

Step 1: Start with what you paid. Your original purchase price, plus the closing costs you paid to buy — title fees, recording, transfer costs, loan origination points. That is your starting basis.

Step 2: Add every capital improvement. This is where sellers leave the most money on the table, because they never kept the receipts. A capital improvement adds value, extends the life of the home, or adapts it to a new use. A repair does not.

Counts: a new roof, a finished basement, a replaced sewer line (very common on Denver's pre-1980 bungalow stock, and routinely $10,000 to $25,000), new windows, a furnace or AC replacement, an added bathroom, a kitchen remodel, a permitted ADU, hardscape and a new driveway. If you upgraded to a Class 4 impact-resistant roof after a hail claim, the portion you paid out of pocket above the insurance proceeds counts.

Does not count: interior paint, a fixed leak, a replaced garbage disposal, annual maintenance.

Step 3: Subtract what it costs you to sell. Real estate commissions, title and settlement fees, Colorado's documentary fee at one cent per $100 of price, and any seller concession you agree to. That last one matters more than it used to. In the Denver metro, roughly 61% of April 2026 closings carried a concession, averaging $9,625. Those dollars come off your amount realized. On a $700,000 Denver sale, selling costs commonly land somewhere between $35,000 and $45,000, and every one of those dollars shrinks your taxable gain.

Step 4: Subtract the exclusion. $250,000 if you file single, $500,000 married filing jointly. You need to have owned the home at least two of the previous five years, lived in it as your primary residence at least two of those five years, and not used the exclusion on another home within the last two years. The two-year windows do not have to be continuous, and they do not have to overlap.

Step 5: Tax whatever is left. For 2026, the federal long-term rate is 0% on taxable income up to $49,450 single and $98,900 married filing jointly, 15% through $545,500 and $613,700, and 20% above that. Add the 3.8% net investment income tax if your modified AGI clears $200,000 single or $250,000 joint — those two thresholds were set by statute in 2013 and have never been indexed for inflation, which is why a one-time home sale drags so many otherwise ordinary earners into them.

Then add Colorado. The state has no separate capital gains rate; the gain is taxed as ordinary income at the flat 4.4%. And here is the piece almost every national article gets wrong for Colorado sellers: HB21-1311 narrowed the old Colorado capital gain subtraction down to taxpayers filing a federal Schedule F, meaning farmers selling agricultural real property. Selling your house in Park Hill does not qualify. There is no state-level break waiting for you.

Three Denver situations where a bill actually shows up

1. Long ownership, and only one name on the return. The National Association of REALTORS estimates 29 million American homeowners — about 34% — already hold enough equity to clear the $250,000 cap, and about 8 million clear $500,000. Denver has been in the top tier of U.S. metros for appreciation over that stretch, so the local share runs higher than the national one. Run it: a Denver home bought for $310,000 in 2012 is worth roughly $796,000 today at the metro's index growth. That is a $486,000 raw gain. A married couple excludes all of it. A single filer, a widow past the two-year window, or two unmarried co-owners are looking at a very different afternoon.

There is a real exception worth knowing. If your spouse died within the last two years and you have not remarried, you can still claim the full $500,000 as a surviving spouse. That one deadline has quietly reshaped the timing of a lot of Denver downsizing decisions.

2. The house was ever a rental, an Airbnb, or had a rented ADU. Depreciation you claimed — or were entitled to claim — comes back as unrecaptured Section 1250 gain, taxed at up to 25%, and the Section 121 exclusion does not cover it. Denver opened ADUs to all residential zone districts in December 2024 and removed the owner-occupancy requirement, so a growing number of Denver owners have been depreciating a rented basement unit or backyard cottage without connecting it to a future sale. Periods of non-qualified use after 2008 also carve the exclusion down proportionally.

3. You already left Colorado. This is the one that ambushes people, and it is the reason I bring it up before a relocating seller signs anything. When a seller's address on the 1099-S or the disbursement authorization is out of state, Colorado requires the title company to withhold on any property sale of $100,000 or more — the lesser of 2% of the sale price or the net proceeds — and remit it to the Colorado Department of Revenue within 30 days, reported on Form DR 1083. On a $700,000 Denver sale, that is up to $14,000 held back at the table.

It is not an extra tax. It is a prepayment credited against your Colorado return, and there are exemptions, including a written affirmation at closing that no Colorado tax will be due. But if you find out about it while you are reading your settlement statement, you have already lost the chance to plan around it. If you are moving out of state and want the full sequence, Nick Ahrens walks relocating sellers through the withholding question at the listing appointment, not the closing.

Two myths worth killing while we are here. You do not roll your gain into your next house — that rule was repealed in 1997 and replaced by the exclusion. And the old over-55 one-time exclusion is gone too. If someone tells you either one still works, they are quoting a tax code that has been dead for nearly thirty years.

Should you wait to see what Congress does?

There is real movement, and you should know about it before you make a timing decision. The More Homes on the Market Act, a bipartisan bill from Representatives Jimmy Panetta and Mike Kelly, would double the exclusion to $500,000 single and $1,000,000 joint and index both to inflation going forward. It is backed by NAR and AARP and sits in the House Ways and Means Committee. A second bill, the No Tax on Home Sales Act, would eliminate the tax on primary residences entirely. The President has publicly floated the idea.

None of it is law as of July 2026.

My honest read: do not build a listing plan around a bill sitting in committee. Interest rates, your equity position, and how long you actually want to keep mowing that lawn are all more knowable than a committee calendar. Run your number first. In most Denver cases it comes back smaller than the fear that generated the question — and if it comes back large, that is exactly the situation where a CPA and a timed sale beat guessing.

If you want a defensible starting point for the sale side of that math, start with what your home is actually worth today rather than an app estimate, since an inflated value inflates your imagined tax right along with it. And keep this separate from your annual property tax bill — that is a recurring cost based on assessed value, not a one-time tax on gain. Sellers conflate the two constantly.

Frequently Asked Questions

Do I avoid capital gains tax if I buy another house in Colorado?

No. The rollover rule that let you defer gain by buying a more expensive home was repealed in 1997 and replaced with the current exclusion. What you do with the proceeds has no effect on whether the gain is taxable.

Does Colorado have its own capital gains tax when I sell my home?

Colorado has no separate capital gains rate. Any gain left after the federal exclusion is taxed as ordinary income at the state's flat 4.4%. The Colorado capital gain subtraction was narrowed by HB21-1311 to taxpayers filing a federal Schedule F, so it does not apply to a primary residence.

What if I only lived in the house 18 months?

You may still qualify for a partial exclusion if the sale was driven by a work location change of at least 50 miles, a health reason, or an unforeseen circumstance such as divorce, death, or job loss. The cap is prorated by months of qualifying use, so 18 of 24 months gives a single filer roughly $187,500 of exclusion.

I moved to Texas last year and I am selling my Denver house now. What happens at closing?

Because your address is out of state, the title company will generally withhold the lesser of 2% of the sale price or your net proceeds and send it to the Colorado Department of Revenue, using Form DR 1083. You claim it as a credit when you file your Colorado return. Exemptions exist, including a written affirmation that no Colorado tax will be owed.

Does the exclusion count the money I still owe on my mortgage?

No. Your loan balance is irrelevant to the calculation. Gain is sale price minus selling costs minus your adjusted basis, and debt appears nowhere in that formula. Two owners on the same street with identical homes and wildly different mortgage balances have the same gain.

How do I prove my capital improvements to the IRS?

Receipts, permits, and contractor invoices. Denver permit records can help reconstruct dated work if you have lost paperwork, and old closing statements establish your starting basis. Start pulling these together before you list, not in April.

Run your number before you list

For most Denver sellers this ends quietly: gain under the cap, nothing owed, no reason to delay a move. For long-tenured single filers, former landlords, and out-of-state sellers, it is a real number that deserves a real calculation and a CPA on the filing side. Either way, guessing at it is the most expensive option available, because the cost of a wrong guess is usually a year of not moving.

I will run the sale-side numbers with you — what your home realistically sells for in today's market, what your selling costs and concessions look like, and what that leaves as a gain — so your accountant is working from real figures instead of a Zestimate. If you also want help choosing the right broker for the job, that guide covers what to ask. And if you are selling a California home on your way here rather than a Denver one, the California capital gains rules and FTB withholding work differently enough to deserve their own read.

Call or text me at 949-230-3625, or email NickAhrensRealEstate@gmail.com, and we will put your actual numbers on paper.

About Nick Ahrens

Nick Ahrens is a Colorado real estate broker with The Apollo Group at eXp Realty, specializing in the Anthem and Baseline communities of Broomfield (80023). With 15+ years in the business and 350+ career closings, he helps North Denver sellers and relocating buyers navigate pricing, timing, and the path to closing. Connect with Nick at youranthemhome.com.