I work with a lot of LA apartment building owners who have held their property for 10, 15, sometimes 30 years. The building is paid off or close to it. The rents have grown. And somewhere in the back of their mind, they know that if they sold tomorrow, a very large percentage of those proceeds would go straight to the government before they ever saw it.

A 1031 exchange is the legal mechanism that changes that outcome. It allows you to sell your apartment building, defer the entire capital gains tax bill, and roll the full proceeds into a larger or better-positioned property. Done correctly, it is one of the most powerful wealth-building tools available to a California real estate investor. Done incorrectly, or done without understanding California’s specific rules, it can fail and leave you with a tax bill you were not expecting.

This guide explains how it works with real numbers, real deadlines, and the California-specific rules that most 1031 guides gloss over. 

If you want to talk through whether a 1031 makes sense for your specific building and situation, you can also read my guide on it.

What a 1031 Exchange Actually Is 

A 1031 exchange, named after Section 1031 of the Internal Revenue Code, allows you to sell one investment property and buy another of equal or greater value without paying capital gains tax on the sale. The tax is not forgiven. It is deferred to a future date, potentially indefinitely.

Here is why that matters with a real number:

Take a 6-unit building in Hollywood purchased in 2004 for $600,000, now worth $2,400,000. After 20 years of depreciation, the adjusted cost basis drops to $400,000, leaving a $2,000,000 taxable gain. 

Without a 1031 exchange, here is what that gain costs you as a California taxpayer in the top bracket, per KDA Inc.:

Tax Component	Rate	Amount Owed
Federal long-term capital gains	20%	$400,000
Federal Net Investment Income Tax (NIIT)	3.8%	$76,000
California state tax (ordinary income rate)	13.3%	$266,000
Federal depreciation recapture	25% on recaptured amount	varies
Estimated combined exposure	up to 37.1%	$742,000+

With a fully executed 1031 exchange, every dollar of that $742,000+ stays inside your next investment and continues compounding. That is not a tax loophole. It is a congressionally authorized strategy that has existed since 1921 and remains fully intact in 2026.

The 45-Day and 180-Day Rules Explained Simply

These are the two deadlines that determine whether your exchange succeeds or fails. Both are absolute. Neither can be extended except in a presidentially declared disaster.

Per Universal Pacific 1031 Exchange and Bay Legal PC:

Deadline	What You Must Do	Consequence of Missing
Day 45	Identify replacement properties in writing to your QI	Exchange fails. Full gain becomes taxable retroactively in the year of sale.
Day 180	Close on a replacement property	Exchange fails. Full gain becomes taxable.

Both deadlines start on the day after your relinquished property closes. They run at the same time, not back to back. You have 45 days to identify and a total of 180 days to close, meaning only 135 days remain after you identify.

The identification rules inside the 45-day window:

You are not picking one property and hoping for the best. The IRS gives you three options for how to identify:

• Three-Property Rule: Identify up to three properties of any value. Most common.
• 200% Rule: Identify any number of properties as long as their combined value does not exceed 200% of your relinquished property’s sale price.
• 95% Rule: Identify unlimited properties if you close on at least 95% of the total identified value. Rarely practical.

One more critical deadline many owners miss: If your 180-day window extends past April 15, the IRS requires you to close the exchange before your tax return due date  (not the full 180 days) unless you file a tax return extension.

What Types of LA Buildings Qualify

Any real property held for investment or business purposes qualifies under Section 1031, as narrowed by the Tax Cuts and Jobs Act of 2018. The standard for “like-kind” is broad: real estate for real estate, regardless of property type, size, or quality.

This means you can exchange:

• A 6-unit RSO building in Hollywood into a 20-unit building in the Valley
• An apartment building in LA into a commercial property in another state
• A single rental property into a portfolio of smaller buildings
• A high-management apartment building into a Delaware Statutory Trust (DST) for a passive, management-free ownership structure

What does NOT qualify:

• Your primary residence (Section 121 has its own separate exclusion rules)
• A vacation home used primarily for personal use
• A fix-and-flip property held primarily for resale rather than investment
• Personal property: the Tax Cuts and Jobs Act eliminated 1031 treatment for non-real-estate assets effective January 1, 2018

For the LA-specific question of RSO buildings: yes, an RSO-covered apartment building qualifies. The rent control status of the building has no bearing on its eligibility under Section 1031. The building’s use as investment real estate is what qualifies it. 

How Measure ULA Interacts with a 1031 Sale

This is the question I get most often from LA owners preparing a 1031 exchange, and the answer is important: Measure ULA is still owed at closing even when you are completing a 1031 exchange.

A 1031 exchange defers capital gains taxes, which are federal and state income taxes on your profit. Measure ULA is a real property transfer tax. A completely separate tax category assessed at the moment of sale within the City of Los Angeles. The two taxes are governed by different laws and have no interaction.

If you sell a $7 million apartment building in Koreatown as part of a 1031 exchange:

• Measure ULA owed at closing: $280,000 (4% of $7,000,000)
• Capital gains tax owed: $0 deferred through the exchange

The ULA tax can be paid from your exchange funds held by the QI without triggering constructive receipt or creating taxable boot, per Treasury Regulation 1.1031(k)-1(g)(7). That means the ULA payment does not disqualify your exchange or reduce the gain you are deferring. It simply reduces the net equity rolling into the replacement property.

The One Mistake That Blows the Exchange

The single most common way LA owners destroy their 1031 exchange is by not hiring a Qualified Intermediary before the sale closes.

If you receive or control the sale proceeds at any point before they are transferred to the replacement purchase, the exchange fails immediately and entirely. There is no cure. There is no do-over. The full gain becomes taxable in the year of sale.

This means:

• You cannot have the proceeds wired to your personal or business bank account, even briefly
• Your attorney cannot hold them in trust on your behalf
• A family member or related party cannot serve as your QI
• Your real estate broker cannot hold the funds

A QI must be a truly independent third party engaged under a formal exchange agreement, in place before the closing of the relinquished property. If you are even thinking about selling, you need to have a QI identified and under agreement before you accept an offer.

The second most common mistake is waiting until after the sale closes to start identifying replacement properties. In LA’s competitive multifamily market, finding the right replacement asset in 45 days while simultaneously managing a closing is extremely difficult. The owners I work with who have the smoothest exchanges are the ones who have replacement targets shortlisted before they list their building for sale.

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