A 1031 exchange boot can turn a tax deferred deal into a partly taxable one, often by accident. Selling an appreciated property outright is already expensive. Federal capital gains, depreciation recapture, the net investment income tax, and state tax can together claim a quarter to a third of the profit, which our complete 1031 exchange guide breaks down in detail.
A 1031 exchange defers all of that by rolling the sale proceeds into a like kind replacement property.
Boot is the catch. It pulls part of the gain back into the current tax year, even when the exchange itself qualifies.
This article covers what boot is, the two forms it takes, how the IRS taxes it, and the steps that keep an exchange fully deferred. We also look at why replacing debt trips up so many investors, and why a single tenant net lease asset makes a clean replacement.
Key Takeaways
- ▸Boot is any sale value you do not reinvest in the replacement property, and it is taxable in the year of the exchange.
- ▸It usually shows up as leftover cash (cash boot) or as a drop in debt (mortgage boot).
- ▸You avoid it with three habits: buy equal or greater in value, reinvest all the equity, and replace all the debt.
What Is Boot in a 1031 Exchange?
Boot is the part of a 1031 exchange that fails the like kind requirement, so it becomes taxable. It usually takes the form of cash the seller keeps or debt that disappears. Boot does not void the exchange. It just makes that slice of the gain due now instead of later.
The term comes from an old English phrase for something extra, the bit thrown in to even out a trade. First Exchange traces it back to bartering.
In a modern deal, boot is simply the leftover value that ends up with the seller instead of in the new property. Kiplinger describes it as the portion that fails the tax free test.
Two facts reassure most investors here. First, boot does not disqualify the whole exchange, so the rest of the gain stays deferred. Second, the IRS taxes boot only up to the amount of the actual gain. Boot cannot create tax on a deal with no profit.
Knowing where boot comes from is the first step to keeping it off the return.
The Two Main Types: Cash Boot and Mortgage Boot
Boot usually shows up in one of two forms. One is obvious. The other is easy to miss.
Cash boot is the straightforward kind. It is any sale proceeds that never reach the replacement property.
Illustrative scenario:
Picture a sale of $1,000,000 and a replacement that costs $950,000. The $50,000 left over becomes cash boot, and the IRS taxes it. Deferred.com uses the same example.
An investor also creates cash boot by pocketing part of the proceeds or buying a cheaper property, and JTC Group explains how a replacement priced below the sale leaves the shortfall exposed.
Mortgage boot, sometimes called debt relief boot, is the sneakier one. It appears when the replacement carries less debt than the relinquished property.
Illustrative scenario:
Suppose the old property had a $400,000 mortgage and the new one carries only $350,000. That $50,000 of debt relief counts as cash received, even though no money changed hands. The IRS treats freedom from debt as an economic benefit, so it taxes the difference unless the investor fills the gap.
A few smaller moves also create boot almost by accident. Universal Pacific flags several common ones:
Loan paydown from proceeds. Paying off a mortgage with sale proceeds can count as boot, because it lowers the amount reinvested.
Closing costs from proceeds. Certain expenses drawn from exchange funds shrink the reinvested amount and create a taxable shortfall.
Prorated rents and taxes. Prorations paid to the seller at closing may read as taxable income rather than exchange proceeds.
None of these looks dramatic alone. Together, they explain why an exchange that looks fully reinvested on paper can still produce a surprise at tax time.
How Is Boot Taxed?
The IRS taxes boot as a capital gain in the year the exchange closes, at the same rates a normal sale would trigger. For 2026, that means a long term rate of 0%, 15%, or 20%. Higher earners also pay the 3.8% net investment income tax, which lifts the top federal rate to 23.8%.
Two wrinkles push the number higher for many owners.
The first is depreciation recapture. The gain tied to depreciation already claimed, known as unrecaptured Section 1250 gain, faces a rate of up to 25%. That rate sits outside the standard brackets, as Reed Corporation explains. Recapture also comes first in the stacking order, so the earliest dollars of boot often land in the 25% bucket rather than the 15% or 20% one.
The second wrinkle is holding period. Property held a year or less loses the long term rates. Instead, boot faces ordinary income rates, which NerdWallet notes can reach 37%. Most accredited investors run exchanges on assets held for years, so the long term rates usually apply. Still, the distinction is worth a check.
There is some good news too. The One Big Beautiful Bill Act preserved the 2026 bracket structure through 2030, so the favorable long term treatment is not set to sunset soon. That stability also makes planning easier, including how much bonus depreciation on the replacement property might offset. Even so, the final tax depends on income, filing status, and state, so treat these figures as a guide rather than a CPA’s math.
How to Avoid 1031 Exchange Boot
You avoid boot by passing a reinvestment test that fits on a napkin. Buy a replacement of equal or greater value, reinvest all the equity from the sale, and replace all the debt you paid off. Miss any one of the three, and the shortfall turns into taxable boot.
The test breaks into three targets, and full deferral generally requires all three. Fidelity and Baker 1031 describe the same standard:
Equal or greater value. The replacement price should match or beat the sale price. Trade down, and the difference is taxable.
Reinvest all equity. Every dollar the qualified intermediary holds should go into the replacement. Pull cash out, and you create cash boot dollar for dollar.
Replace all debt. The new loan should equal or exceed the old one. If it falls short, add fresh cash to cover the gap.
A few habits protect those targets.
Never take possession of the sale proceeds. Touching the money can void the exchange entirely, not just create boot. Leave the funds with the qualified intermediary, and report the deal to the IRS on Form 8824.
Plan for closing costs and prorations early, too. That way they do not come out of the exchange proceeds and open a shortfall.
The deadlines also leave little room. An investor has 45 days to identify replacements in writing and 180 days to close. Courts treat those dates as firm lines that ignore financing delays and holidays, as Universal Pacific points out.
Why Replacing Debt Is the Hardest Part
Of the three targets, replacing debt catches experienced investors off guard most often.
Cash boot is easy to see, because the money is sitting right there. Mortgage boot is different. It can appear even when every dollar of equity goes back in. An investor who sells a leveraged property and buys one with a smaller loan has reinvested all the cash, yet still owes tax on the debt that vanished.
There are two ways to close the gap, and each has a tradeoff. The investor can add new cash to replace the missing debt. That works cleanly, but it ties up more capital than planned. Or the investor can take on a larger loan, which protects liquidity. The catch is that the financing has to match or beat the prior debt, and it has to close inside the 180 day window.
For an individual buyer, arranging that loan on institutional terms and on a tight schedule is usually the sticking point.
A family office structure changes the math here. Custom Capital pairs each investor with a programmatic institutional lending facility. In plain terms, that means pre approved financing across a wide lender network, not a fresh loan hunt for every deal. Because the terms are set ahead of time, an investor can place debt on the replacement that equals or beats the debt being retired. That is exactly what cancels mortgage boot. The firm handles the sourcing and financing so the debt piece is solved before the clock runs out.
Learn More About Working with Custom Capital →
Why Absolute NNN Makes a Clean 1031 Replacement
An absolute NNN property is a single tenant asset where the tenant pays taxes, insurance, and maintenance. It makes a clean replacement because an investor can move all the equity and debt into one asset. Ownership stays low effort, and the deal checks the reinvestment boxes without splitting capital across several properties.
Absolute NNN is not the only route, to be fair.
Some investors use Delaware Statutory Trusts to absorb leftover proceeds and mop up cash boot. Others buy several smaller properties to reach the value target. Both options have their place, especially for investors who want fractional exposure or a backstop inside the 45 day window. The tradeoff is added complexity. Fractional and multi property deals bring shared ownership rules, multiple closings, and less control.
For an investor who wants full deferral with limited work, a single net lease property as the 1031 replacement tends to fit better. One purchase can absorb the whole sale price and the replacement debt. The tenant carries the operating load. Income generally starts in the first month of ownership.
The hard part is speed. The 45 day identification clock does not pause while an investor searches the open market.
That is where sourcing matters. Custom Capital works from off market inventory it has already vetted, which shortens the search that so often collides with the deadline. Across more than $460M in acquisitions and 125+ closed deals, the firm has focused on matching accredited investors to single tenant NNN assets that suit an exchange, rather than sending them to chase listings under pressure.
Final Thoughts: Boot Is Avoidable With a Plan
Boot is not a penalty for a botched exchange. It is simply the value that falls outside the deferral, whether that is leftover cash or debt you did not replace.
The habits that prevent it do not change: go equal or greater on value, reinvest every dollar of equity, and match or exceed the old debt. Depreciation recapture and the 2026 rates make a miss costly, so the planning usually pays for itself.
Planning a 1031 Exchange?
Map the numbers before a sale, not after. Work through the value, equity, and debt math with our team, and find a replacement that keeps the exchange fully deferred.
Frequently Asked Questions
What is boot in a 1031 exchange?
Boot is any sale value that does not go into the like kind replacement property, such as leftover cash or reduced debt. It does not cancel the exchange. It just makes that portion of the gain taxable in the year the deal closes, as Kiplinger explains.
Is boot taxed as ordinary income or capital gains?
Usually as a capital gain. For 2026, the long term rates are 0%, 15%, or 20%, and higher earners add the 3.8% net investment income tax. If the owner held the property a year or less, boot faces ordinary income rates instead, which NerdWallet notes can reach 37%.
Can you do a partial 1031 exchange?
Yes. An investor can reinvest some proceeds and keep the rest, a move often called a partial exchange. The reinvested portion stays deferred, while the amount kept back becomes taxable boot. JTC Group walks through how that shortfall gets taxed.
Do closing costs paid from proceeds create boot?
They can. Expenses drawn from exchange funds lower the reinvested amount and may count as taxable boot, and prorated rents or taxes can read the same way, as CPA Nerds describes. Planning for these costs separately helps avoid a surprise.
How do you avoid mortgage boot?
Place debt on the replacement that equals or exceeds the debt you paid off, or add new cash to cover the difference. Either move offsets the debt relief the IRS would otherwise tax. Deferred.com recommends matching debt levels for this reason.
