Carmen bought a rental for $220,000 twelve years ago and just accepted an offer for $380,000. She'd read enough landlord content to know depreciation recapture would take a real bite, and she braced for it. The recapture-plus-capital-gains-plus-NIIT bill came to $41,066 — a genuine number, but less than a third of the $207,666 gap between her sale price and what actually lands in her account. The other two-thirds is the $140,000 she still owes on the mortgage, a number that has nothing to do with tax at all.
The Math Most Landlord Content Skips
Most of what gets written about selling a rental focuses entirely on the tax side — depreciation recapture, capital gains brackets, NIIT — because that's the part with rules worth explaining. Carmen's case uses the same three-layer tax calculation, but it exists specifically to show what happens when a landlord still owes a meaningful mortgage balance, which the tax math never touches and most worked examples skip by assuming the property is paid off.
Layer 1: Depreciation Recapture
Carmen allocated 80% of her $220,000 purchase price to the building. Over 12 years of straight-line depreciation on a 27.5-year schedule:
$220,000 × 80% ÷ 27.5 = $6,400/year × 12 years = $76,800 in accumulated depreciation.
That $76,800 is recaptured first, taxed at a rate capped at 25% — a ceiling, not a flat rate, applied through the graduated brackets once stacked on Carmen's $75,000 of other income. For her numbers, that works out to $17,818, an effective rate of about 23.2%.
Layer 2 & 3: Capital Gains and NIIT on What's Left
| Sale price | $380,000 |
| − Selling costs (7%) | −$26,600 |
| − Adjusted basis ($220,000 − $76,800 depreciation) | −$143,200 |
| Total gain | $210,200 |
| − Depreciation recapture (taxed above) | −$76,800 |
| Remaining long-term capital gain | $133,400 |
With $75,000 of other income plus this gain, Carmen's income lands at $208,400 — inside the 15% long-term capital gains bracket: $133,400 × 15% = $20,010.
Her modified AGI including the full $210,200 gain comes to $285,200 — $85,200 over the $200,000 single-filer NIIT threshold. NIIT applies to the smaller of her total gain or that overage: $85,200 × 3.8% = $3,238.
Total federal tax: $17,818 + $20,010 + $3,238 = $41,066.
The Number That Actually Dominates: The Mortgage
Here's where Carmen's case diverges from a paid-off-property example. Net proceeds aren't sale price minus tax — selling costs come off first, and then any remaining mortgage balance comes off after that, before tax even enters the picture conceptually:
| Amount | |
|---|---|
| Sale price | $380,000 |
| − Selling costs (7%) | −$26,600 |
| − Mortgage payoff | −$140,000 |
| − Total federal tax | −$41,066 |
| Net proceeds to Carmen | $172,334 |
The mortgage payoff is $140,000. The entire federal tax bill is $41,066 — roughly a third the size. If Carmen had been debt-free on this same property, she'd have walked away with $312,334 instead — a $140,000 difference that has nothing to do with the IRS.
Why This Matters for How Landlords Should Actually Prepare
Carmen did the right preparatory work on the tax side — she looked up depreciation recapture, understood it wasn't a flat 25%, and had a real number before accepting an offer. What she hadn't lined up with the same precision was a current mortgage payoff statement, because it felt like a known, boring number rather than something to research. For a landlord still carrying debt on a rental, the payoff statement from the lender — not the tax estimate — is usually the bigger lever on what actually lands in the bank account, and it's also the easier of the two numbers to get exactly right: a phone call or a login, rather than a tax calculation.
What This Doesn't Include
Every number above is federal tax only; state capital gains tax (0% to over 13% depending on the state) isn't included and doesn't interact with the mortgage payoff at all — that comes straight off the top regardless of state. This also assumes straight-line depreciation from basic inputs; a cost-segregation study or improvements added later would change the accumulated-depreciation figure and the recapture tax that depends on it, though it wouldn't touch the mortgage line either.
Run Your Own Numbers
Whether you still carry a mortgage, and how much, can easily matter more to your actual proceeds than the tax questions most rental-sale content focuses on. Put your own purchase price, hold period, sale price, and current mortgage balance through the Sell vs Keep Rental Calculator to see your full picture — tax and debt together, not just one of them.
Frequently Asked Questions
Does the size of the mortgage affect how much tax Carmen owes?
No — this is the detail that trips people up. Recapture, capital gains, and NIIT are all calculated from sale price, selling costs, and adjusted basis; the mortgage balance never enters that formula. Carmen would owe the same $41,066 whether she had $140,000 left on the loan or had paid it off completely years ago. The mortgage only changes what's left over after tax, not the tax itself.
Why didn't Carmen's recapture hit the full 25% rate?
Because 25% is a ceiling that applies only to the slice of recaptured gain that would sit above the top of the 24% ordinary bracket once stacked on her other income — and at $75,000 of other income with $76,800 of recapture, none of hers climbs that high. A landlord with more other income, or a larger recapture amount, would see a bigger share taxed at the full 25%.
Would it have made more sense for Carmen to pay down the mortgage before selling instead of just paying it off at closing?
Generally no, unless she had a specific reason tied to loan terms (like a prepayment penalty that disappears closer to payoff, or wanting to qualify for different financing in the meantime) — paying it down earlier with cash just moves money from a bank account into home equity sooner, and it comes out the same way at the closing table either way. The $140,000 leaves her net proceeds regardless of when it was paid down, since it's the same balance either way.
Is a 7% selling-cost estimate realistic for Carmen's situation?
It's a standard planning estimate covering commissions, closing costs, and title fees, consistent with typical ranges — but actual costs vary by market, agent commission negotiation, and specific closing details. Sellers close to a real decision should get an actual estimate from a title company or their agent rather than relying on a round planning number for a sale this size.
If Carmen refinanced and pulled cash out before selling, would that change this math?
It would change the mortgage payoff line directly — a larger balance from a cash-out refinance means more comes off net proceeds at closing, dollar for dollar. It would not change the tax calculation at all, since recapture, capital gains, and NIIT are based on the sale price and basis, not on how much debt sits against the property or what the borrowed cash was used for.