The 1031 Exchange Across State Lines

Section 1031 of the Internal Revenue Code defers gain when property held for productive use in a trade or business or for investment is exchanged for like-kind property [1][2]. A primary residence is personal-use property, so it has never qualified, and the tax law that protects your family home is the separate Section 121 exclusion, covered thoroughly in our capital gains timing guide [7]. The two rules serve different properties and cannot be combined on the same asset.

In practical terms, that gives a California-to-Texas family two separate engines. The home they live in sells under Section 121, with up to $500,000 of gain excluded (married filing jointly) and no replacement requirement [7]. A rental they own, if any, can sell under a 1031 into a Texas investment property, deferring its gain entirely [1]. Mixing the two up, or assuming a 1031 covers the house, is the most common mistake in this whole conversation, and it is expensive when it happens [1][2][7].

A 1031 is a deferred sale, not an exchange in the old door-for-door sense, and the law runs it on two unrenewable clocks that start the day the relinquished property transfers [1][3]. Count carefully, because the IRS does not extend either one for any reason.

• The 45-day identification period. You must identify the replacement property in writing to the qualified intermediary, or the seller of the potential replacement, by midnight of the 45th day after the transfer of your California property [1][3]. Identification is not an intent to buy; it is a written list with addresses and legal descriptions.
• The 180-day exchange period. You must receive the replacement property by the earlier of 180 days after the transfer or the due date, including extensions, of your tax return for the year of the transfer [1][3]. A late October California sale can file into an April tax deadline, which shortens the real window, so calendar the return date, not just the 180.

The identification rules themselves have three safe harbors: the three-property rule (up to three candidates of any value), the 200% rule (any number of candidates whose total value does not exceed 200% of the relinquished property's value), and the 95% rule [3]. For a California landlord shopping the Texas Hill Country, the practical move is to identify two or three Texas properties early, then close on the one that passes inspection.

Here is the rule that surprises almost every client, including the ones who have already done an exchange: when California real property is exchanged for like-kind property outside California, the state keeps its claim on the deferred gain, and it tracks that claim through an annual filing requirement [4][5][8]. Since 2014, a taxpayer who exchanges California real estate into out-of-state property must file Form FTB 3840 with their California return in the year of the exchange and every subsequent year until the California-source deferred gain is recognized [4][5].

Notice what this does not depend on: your residency. The obligation applies whether you still live in California or have been a Texas resident for a decade [4][5]. Moving to Texas stops California from taxing your Texas wages, but it does not stop California from taxing the gain it already earmarked on property that used to sit inside its borders. Under Revenue and Taxation Code Section 18032, the state's reach over that deferred gain is preserved until the replacement property is sold [8].

The practical effect is an annual chore, not a tax bill. Each year until you sell the Texas rental, a Form FTB 3840 goes with your California filing, reporting the identity of the replacement and the deferred gain attached to it [4][5]. File it, and the record stays clean. Skip it, and the state's billing system wakes up years later with interest. This is the quiet reason I tell landlords with California rental property to budget for a California tax preparer for as long as they hold an exchanged Texas asset [4][5][8].

A 1031 works only if the sale proceeds pass through a qualified intermediary, a third party that holds the funds between the two closings [1][2]. If the proceeds land in your bank account, even for a weekend, or if you receive anything of value from the buyer before the replacement closes, the exchange is disqualified and the full gain becomes taxable in the year of the California sale [1][2].

The mechanics feel counterintuitive to anyone who has sold a normal home: you instruct the escrow company to wire directly to the intermediary, the intermediary wires to the Texas seller at closing, and you never see the money pass through your accounts. Debts also flow: the replacement property must generally carry at least as much debt as the relinquished one, or the difference in net equity relief is taxable as boot [1]. For a California landlord who has paid the mortgage way down, matching debt on the Texas side often means taking a new loan on the replacement, and the qualified intermediary coordinates that too.

The deferral is only worth its size when you can see it. Take an ordinary California rental: a Bay Area duplex purchased years ago at a low basis, with accumulated depreciation taken along the way, selling today at a strong price. Every line below is stated so you can run your own numbers; the rates are the 2026 federal brackets and California's ordinary-income treatment of capital gains [9][10][11].

If this landlord sells outright, the tax stack runs three layers. Federal: 25% on the $150,000 recapture piece is about $37,500, and 20% on the $478,000 long-term slice (top bracket, income over the threshold) is about $95,600 [9][11]. The 3.8% net investment income tax adds about $23,900 on the whole $628,000 gain for households above the MAGI threshold [9]. California, which taxes capital gains as ordinary income with a top rate of 13.3%, claims roughly $83,500 [10]. The combined bill is near $240,500.

Roll the same sale into a Texas rental through a 1031, and that $240,500 stays in your pocket, compounding inside the replacement property [1]. The trade is that the basis carries over: your Texas rental inherits the low $500,000 adjusted basis, so the eventual sale, whenever it happens, will surface the full gain, including the California-attributed piece that Form 3840 has been tracking each year [4][5]. The deferral is a loan from the tax code with no interest rate and no due date, but it is not a forgiveness [1][4][5].

The other side of the exchange deserves the same scrutiny as the tax math. San Antonio remained the most affordable large Texas metro in 2026, with median home prices in the mid-$200s to low-$300s, and Hill Country towns nearby at a premium [12][14]. Commercial multifamily cap rates in San Antonio averaged about 5.2% in mid-2026, while well-underwritten single-family rentals in the broader market have been modeled in the 6% to 9% going-in range, which is why a California landlord's $1.1 million of equity often reaches further here than in the Bay Area [12][14].

The line that changes the underwriting is property tax, because rentals get no homestead exemption [13]. A residence homestead saves an owner the mandatory $140,000 school-district exemption and the 10% appraisal cap; an investment property pays the full combined rate, typically in the 2.3% to 2.7% range across the San Antonio area after the first year's reappraisal [13]. On a $450,000 Texas rental that is roughly $10,350 to $12,150 a year before insurance and management [13]. The numbers still work against Bay Area norms, but they work only when the buyer underwrites Texas taxes as a landlord, not as a homeowner [12][13][14].

A practical note for anyone shopping the Hill Country: the exchange identifies a property by day 45 and closes by day 180, and a well-and-septic due diligence cycle can take the better part of that window. Identify real candidates early, have the inspections queued, and treat the 45th day as the day you commit to a short list, not the day you start looking [1][3].

The most common plan I hear from landlords is not renting the Texas property forever. It is exchanging into a Texas rental, holding it for a while, and then moving into it themselves. That plan works, but only under the Revenue Procedure 2008-16 safe harbor, and only if the rental period is real [6].

The safe harbor asks three things of the replacement dwelling: you must own it for at least 24 months; in each of the two 12-month periods after the exchange, you must rent it at fair market value for at least 14 days; and your personal use cannot exceed the greater of 14 days or 10% of the rental days [6]. Rent a Texas house for a genuine year with tenants and a lease, and you can convert it in the second year. Buy it, let a relative stay rent-free, and the exchange can be challenged [6]. The pattern also affects a future Section 121 exclusion on the eventual sale, so the conversion plan deserves a CPA conversation before you identify the property, not after [6][7].