A 1031 exchange (also called a like-kind exchange) works by routing your sale proceeds through a qualified intermediary rather than receiving the cash directly. Because you never technically touch the money, the IRS treats the transaction as a continuation of your investment rather than a liquidation event. The result: the capital gains tax bill that would normally come due on a profitable sale gets pushed forward until you eventually sell a property outside of a 1031 structure. Investors who execute sequential 1031 exchanges over a lifetime can defer taxes indefinitely, and heirs who inherit the property receive a stepped-up cost basis, potentially eliminating the deferred liability entirely.
The IRS imposes two hard deadlines you must hit or the exchange collapses. First, you have 45 days from the closing date of the relinquished property to formally identify up to three potential replacement properties in writing. Second, you must close on one of those identified properties within 180 days of the original sale (or the tax-filing deadline for that year, whichever comes first). There is no flexibility on either deadline. The replacement property must be of equal or greater value, and all of the equity from the sale must be reinvested. If you receive any leftover cash (called "boot"), that portion is taxable in the year of the exchange. The formula for determining taxable boot is straightforward: Taxable Boot = (Sale Price of Relinquished Property) - (Purchase Price of Replacement Property) + (Any Cash Received). In notation: Boot = Sale Price - Replacement Cost + Cash Out.
Not every property qualifies. The exchange must involve property held for investment or productive use in a trade or business on both sides of the deal. Primary residences, vacation homes used primarily for personal enjoyment, and properties held primarily for resale (fix-and-flip inventory) do not qualify. Rental properties, commercial buildings, raw land held for appreciation, and even certain leasehold interests generally do qualify. The "like-kind" standard is broader than most investors expect: you can exchange a single-family rental for a retail strip center, or a piece of farmland for an apartment building, as long as both properties are located within the United States and meet the investment-use test.
Worked example
A landlord sells a duplex in Phoenix for $600,000. The original purchase price was $200,000, so the gain is $400,000. At a combined federal and state capital gains rate of roughly 28%, the tax bill on a straight sale would be approximately $112,000. Instead, the landlord engages a qualified intermediary before closing, directs the $600,000 into escrow, and within 45 days identifies a six-unit apartment building in Dallas listed at $750,000. The landlord closes on the Dallas property within 180 days, bringing an additional $150,000 in cash to cover the difference. Because the replacement property is worth more than the relinquished one and no boot is received, the entire $112,000 tax bill is deferred. The landlord now controls a larger asset, retains liquidity that would have gone to taxes, and the deferred gain carries forward as a reduced cost basis in the new property.