He Sold the Duplex to His Daughter for $540,000 and Took It Back in Fifteen Years of Monthly Checks. The Rent Pays the Note, and Most of Each Year’s Slice of Gain Has Landed in His 0% Bracket Since 2019

Owners of a rental property that has gained significant value can sell to a family member, with the owner acting as the lender and paying tax on the gain only as payments come in. This is called an installment sale. If the seller’s other income is low, much of each year’s gain can fall into the 0% long-term capital gains bracket. In the case behind the headline, a father sold a duplex to his daughter for $540,000 in 2019 on a 15-year note. Rent from the second unit covers her monthly payment, while his gain shows up on his tax return piece by piece each year instead of all at once.

Every Payment Carries a Fixed Slice of Taxable Gain

Under the installment method, each principal payment has two parts. The first part returns the seller’s basis (about what he paid for the property, adjusted over time) tax-free. The other part is taxable gain. The split is set at closing as the gross profit percentage: total profit divided by the contract price.

It stays the same for the life of the note, and so interest on the note is taxed separately as ordinary income. Meanwhile, long-term gain is taxed at 0% as long as taxable income stays below a limit set by law, so spreading a large gain over 15 years can keep each year’s piece small enough to fit under that limit.

Three Code Sections That Make It Work

Section 453(c) of the Internal Revenue Code defines the installment method as taxing “that proportion of the payments received in that year which the gross profit (realized or to be realized when payment is completed) bears to the total contract price.” Section 1001(d) confirms that the gain portion is taxed “in the year in which such payment is received.”

The 0% rate comes from Section 1(h), through the “maximum zero rate amount” in Section 1(j)(5). That amount has been indexed for inflation after 2018. Revenue Procedure 2025-32 sets the 2026 limit at $49,450 single / $98,900 joint. Sellers report the sale on Form 6252 each year.

Family Buyers Qualify While Controlled Entities Lose the Deferral

A daughter counts as a “related person” under Section 453(f)(1), which uses the family ownership rules in Section 318(a). That label alone still allows installment reporting. A harsher rule, Section 453(g), treats all payments as received in the year of the disposition when depreciable property is sold between related persons.

That rule uses a narrower definition from Section 1239(b): controlled entities, trusts in which the seller or spouse is a beneficiary, and executors dealing with estate beneficiaries. A sale to a child as an individual falls outside that list. A sale to an LLC the seller controls, or to a trust he benefits from, generally falls inside it. The 0% piece also requires low taxable income, because gain is counted on top of wages, pensions, and interest.

Setting Up a Family Installment Sale in 2026

1. The property is typically priced at its appraised fair market value. Selling below market can be treated partly as a gift. The 2026 annual gift exclusion is $19,000 per recipient.
2. Charge at least the applicable federal rate (AFR), the minimum interest rate the IRS publishes each month. For October 2026, the long-term AFR is 5.22% with annual compounding and 5.10% with monthly compounding. If the stated rate is lower, Sections 483 and 1274 let the IRS treat part of each principal payment as interest.
3. Sign a promissory note and record a mortgage or deed of trust to secure the seller’s claim with the property.
4. File Form 6252 every year. Report interest as ordinary income on Form 1040, line 2b. If the buyer lives in the property, Schedule B must list her name, address, and Social Security number, or the seller can face a $50 penalty.
5. Keep taxable income under the 0% limit. The 2026 standard deduction is $32,200 for joint filers and $16,100 for single filers.

Depreciation Gets Taxed First, Ahead of Any 0% Gain

Years of rental depreciation affect how each payment is taxed. Section 453(i) requires any recapture income to be recognized in the year of the disposition, even if no cash comes in that year. For residential rentals depreciated on a straight-line basis, ordinary recapture is often zero. The depreciation still shows up as unrecaptured Section 1250 gain, which is taxed at ordinary rates limited at 25%.

Treasury regulation 26 CFR 1.453-12(a) says this gain “is taken into account before the adjusted net capital gain.” So the early payments carry the depreciation layer first. For a low-income seller, that layer is taxed at 10% or 12%, and the 0% rate applies only after it runs out. Under that order, the 0% rate applies to the gain remaining after the depreciation layer is taxed.

Two more rules apply to related-party installment sales. Under Section 453(e), if a related buyer resells within 2 years, the seller is treated as receiving the resale proceeds right away. For a 2019 sale, that window closed long ago. If the daughter stops paying and he takes the duplex back, Section 1038 determines how much gain he reports when he takes it back.

Higher Rates Change the Math for New Notes

Minimum rates for new family notes have climbed through 2026. The long-term AFR rose from 4.87% in June to 5.22% in October. The 10-year Treasury yield was 5.21% on October 13. A note signed now requires more interest. That interest is ordinary income, and it uses up the lower brackets before any gain is counted. A note signed in 2019 keeps its original rate for the full term.

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