Why It Matters
Here's the key thing to understand: a partial exchange isn't a failed exchange — it's a deliberate trade-off. You can pocket some cash (or trade down to a smaller property) and still defer taxes on the gain you didn't cash out. The portion you cash out becomes taxable as boot, while the rest stays deferred. Depreciation recapture gets taxed first at 25%, before any capital gains rate applies to the remaining boot. For investors who need liquidity or want to simplify their portfolio, a partial exchange can be the right move — as long as you size the tax hit correctly before you close.
At a Glance
- What it is: A 1031 exchange where some proceeds aren't reinvested, creating taxable boot alongside a tax-deferred gain
- Why it matters: Lets investors access equity or trade down without forfeiting all 1031 benefits
- Key rule: To defer ALL taxes, you must reinvest 100% of net proceeds AND take on equal or greater debt on the replacement
- Boot trigger: Any shortfall on equity reinvestment or debt replacement becomes taxable boot
- Tax order: Depreciation recapture (25%) is recognized before long-term capital gains rate applies
Taxable Boot = Lesser of (Boot Received) or (Realized Gain)
How It Works
The full-exchange requirement — and what breaks it. A full 1031 exchange requires two things: you reinvest every dollar of net equity from the sale, AND the replacement property carries at least as much debt as the relinquished property. Break either condition and you have a partial exchange — the shortfall becomes boot, taxable in the year of the exchange. The rest of the gain stays deferred. What most investors miss is that both conditions must hold simultaneously; meeting just one isn't enough to achieve full deferral.
The three types of boot. Cash boot is the most intuitive — you receive cash at closing, or you don't reinvest all net proceeds into the replacement. Mortgage boot is subtler: if the replacement property carries less debt than the property you sold, the debt reduction counts as if you received cash. Sell with a $300,000 mortgage, buy with a $150,000 mortgage — that's $150,000 of mortgage boot, taxable regardless of whether cash changed hands. Personal property boot (receiving non-like-kind property as part of the deal) is rare but follows the same rule. The good news: cash and mortgage boot offset each other. Add enough cash to the replacement deal to compensate for the lower debt, and you neutralize the mortgage boot dollar-for-dollar.
How the tax is calculated. The taxable portion is always the lesser of (boot received) or (realized gain) — you can't be taxed on more gain than you actually made. Within that taxable amount, depreciation recapture gets hit first at 25%, before the long-term capital gains rate applies to any remainder. Your 1031 exchange advisor and CPA should run this calculation before you finalize the replacement property, because the tax bill can be larger than it looks when depreciation recapture is significant. The qualified intermediary still holds the exchange proceeds according to exchange rules — a partial exchange isn't exempt from the standard timeline and identification requirements.
Real-World Example
Diane owns a duplex she bought for $180,000 eight years ago. She's claiming it for $410,000. Her realized gain is $230,000, and after depreciation she's got about $47,000 of recapture exposure.
She wants to simplify — her target replacement is a smaller single-family rental for $287,000 with a $160,000 mortgage. The relinquished duplex had a $195,000 mortgage. That $35,000 debt reduction becomes mortgage boot. And because she's netting $215,000 from the sale but only reinvesting $127,000 of equity, she's also pocketing $88,000 in cash boot. Total boot: $123,000.
Taxable gain = lesser of $123,000 boot or $230,000 realized gain = $123,000. The depreciation recapture ($47,000) is taxed first at 25% — that's $11,750. The remaining $76,000 of boot is taxed at her long-term capital gains rate of 15%, or another $11,400. She writes a check for roughly $23,150 and defers the other $107,000 of gain. Not a free lunch — but compared to selling outright and paying taxes on the full $230,000, the partial exchange saves her a meaningful amount.
Pros & Cons
- Lets you access equity or extract liquidity without forfeiting all 1031 tax deferral benefits
- Works when you want to trade down in portfolio size without a full taxable sale
- Boot amount is flexible — you control how much to receive by adjusting how much you reinvest
- Cash boot and mortgage boot offset each other, giving you tools to manage the tax hit
- Still requires only a single QI and follows the same timeline as a full 1031 exchange
- Depreciation recapture at 25% can make the tax bill larger than investors expect
- Mortgage boot can trigger taxes even when you receive no cash — a common surprise
- Doesn't eliminate capital gains on boot — it just defers the rest, so you still need to plan for the tax payment
- Requires accurate forecasting before closing — the math must be done in advance, not after
- Adds complexity to tax filing in the exchange year; professional CPA involvement is non-negotiable
Watch Out
- Recapture before capital gains: Depreciation recapture is recognized first at 25%, before any preferential capital gains rate. Investors who only calculate their capital gains rate often underestimate the total tax hit. Run both calculations.
- Mortgage boot is invisible cash: Reducing your debt load on the replacement triggers the same tax consequence as pocketing cash. If you're planning to "trade down" without realizing you're also reducing debt, you may owe taxes you didn't budget for.
- Timing is fixed: A partial exchange is still a 1031 exchange — the 45-day identification window and 180-day closing deadline from exchange rules apply in full. The boot doesn't buy you extra time.
- Offset strategy requires advance planning: Adding cash to the replacement to offset mortgage boot only works if it's structured before closing. You can't retroactively fix it after the exchange closes.
Ask an Investor
The Takeaway
A partial exchange is a legitimate, deliberate strategy — not a mistake. When you need liquidity, want to trade down, or can't fully replace your debt, you can still defer a substantial portion of your gain while accepting a smaller, manageable tax bill on the boot. The math must be right before you close: depreciation recapture comes first at 25%, mortgage boot counts even when no cash changes hands, and cash can offset mortgage boot if you plan for it. Work with your 1031 exchange advisor before you sign anything.