Is there a minimum value for my replacement property?

The statute has no price floor, only a rule for what you take out

Section 1031(a) defers gain when real property held for investment or business is exchanged for like-kind real property, and the Form 8824 instructions say real properties are generally like-kind whether improved or unimproved. Nothing in either sets a minimum price, value ratio or property size.

Section 1031(b) supplies the cost of buying less: if you also receive money or other property, gain is recognized up to that amount. Publication 544 calls this a partially nontaxable exchange and caps recognized gain at the smaller of your realized gain and the money and other property received, less exchange expenses.

So a smaller replacement does not break the exchange. It simply leaves part of the value outside it. The same holds when the replacement is several smaller properties: their values are added together, and only the combined total is compared with what you sold. Your intermediary will not refuse a cheaper purchase; it pays out the unused balance when the regulations allow, usually after you have received everything you identified or the exchange period has run out.

The shortfall shows up as leftover cash, unreplaced debt, or both

Cash the intermediary still holds when you finish buying is boot; the mechanics of that remainder are in leftover cash after a 1031.

Debt counts too. Reg. section 1.1031(d)-2 treats liabilities you are relieved of as money received, and its Example 2 lets cash you pay or debt you take on offset that relief. Cash you receive is not offset by new debt.

Put together, if you use every dollar of proceeds, the boot equals your net sale price minus the replacement's value. That is why the target in reinvest the whole sale price or the gain is the price, not the gain.

Worked example: a $1,000,000 sale traded down to $800,000

Hypothetical, round figures, closing costs ignored. You sell for $1,000,000, pay off a $300,000 mortgage, and $700,000 goes to the intermediary. Your adjusted basis is $400,000, so the realized gain is $600,000, of which $150,000 is depreciation.

You buy an $800,000 property. With $700,000 of cash and a $100,000 loan, net debt relief is $200,000 and you recognize $200,000. With $600,000 of cash and a $200,000 loan, $100,000 of cash is left over and net debt relief is $100,000, so you again recognize $200,000.

Either way the $200,000 shortfall in value is the taxable amount, and it comes first from the $150,000 depreciation layer, taxed at up to 25% under Topic 409. The ordering is explained in boot taxed as recapture or capital gain first. Run your own numbers with your CPA.

• Replacement at $1,000,000 or more: $0 recognized.
• Replacement at $800,000: $200,000 recognized, $400,000 deferred.
• Replacement at $400,000 or less: the full $600,000 is recognized, so the exchange defers nothing.

Your adjusted basis is the practical floor below which an exchange is pointless

Because recognized gain is capped at realized gain, buying a replacement worth less than your net sale price minus your gain, which is roughly your adjusted basis, makes the boot exceed the gain and the whole gain taxable. You would carry a low basis forward for no benefit.

Between the basis and the sale price, every dollar of extra replacement value defers a dollar of gain. Decide whether the deferral is worth the replacement's costs; is a small gain worth a 1031 runs that test.

Planned trade-downs, where you take some cash on purpose, are covered in trading down with a 1031.

Identification limits cap the top, and a fractional interest fills the gap

The rules restrict how much you may name, not how little. Reg. section 1.1031(k)-1(c)(4) allows three properties of any value, or any number whose combined value does not exceed 200% of what you sold, and otherwise requires you to acquire 95% of what you named.

Where the property you want is worth less than your target, the difference can be closed with a second identified property. A beneficial interest in a Delaware Statutory Trust, which Rev. Rul. 2004-86 treats as real property for the exchange, can be bought in an amount set by you rather than by the market for whole buildings, subject to each offering's own minimum.

A trust interest is illiquid, carries sponsor fees and depends on its tenants and lender. See traditional DST solutions before naming one.