The capital gains exemption in California isn’t a single rule—it’s a short list of federal exemptions and deferrals that the state partially honors, plus a few places where California breaks from federal law and taxes gains the IRS would let you keep. Every dollar of capital gain is treated as ordinary income on your California return, taxed through the state’s progressive brackets up to 13.3% at the top.1Franchise Tax Board. Capital Gains and Losses There is no long-term rate, no general exclusion for investment gains. What follows is what you can actually use to reduce or defer that bill, and where California will still come after you even when the IRS doesn’t.
Selling Your Primary Residence
The biggest break available to most Californians is the exclusion for selling the home you live in. Under Internal Revenue Code Section 121, you can exclude up to $250,000 of gain as a single filer, or $500,000 if you’re married filing jointly, from both your federal and California income.2Office of the Law Revision Counsel. 26 U.S. Code 121 – Exclusion of Gain from Sale of Principal Residence California conforms fully, so meeting the federal tests covers both returns.
Two tests have to be satisfied during the five-year period ending on the sale date. You must have owned the home for at least two of those five years, and you must have lived in it as your principal residence for at least two of those five years. The two years of use don’t need to be consecutive. You can only use the exclusion once every two years.2Office of the Law Revision Counsel. 26 U.S. Code 121 – Exclusion of Gain from Sale of Principal Residence
For married couples claiming the full $500,000, both spouses must meet the use test, though only one spouse needs to meet the ownership test. Second homes, vacation properties, and investment real estate do not qualify.
Partial Exclusion When You Sell Early
If you sell before hitting the two-year marks because of a job relocation (generally more than 50 miles), a health condition, or certain other unforeseen circumstances, a prorated exclusion may still be available. The amount is based on how much of the two-year requirement you completed. A single filer who lived in the home for one year before a qualifying job move could exclude $125,000; a joint return in the same situation, $250,000. Military members moving for service commitments get additional flexibility.
If the Home Was Ever a Rental
This is where the exclusion quietly shrinks. If you bought a property, rented it out for several years, then moved in and later sold it, you cannot exclude the full gain. The portion of your ownership period that counts as “non-qualified use”—time the property wasn’t your principal residence—reduces the excludable gain proportionally. Own a home for ten years but live in it for only five, and roughly half the gain falls outside the exclusion. Non-qualified use before January 1, 2009 is disregarded. Separately, any gain attributable to depreciation you claimed while renting is never eligible for the Section 121 exclusion and will be taxed regardless.
Deferring Investment Property Gains Through a 1031 Exchange
Real estate investors can defer capital gains by rolling the proceeds from one investment property into another through a Section 1031 like-kind exchange.3Office of the Law Revision Counsel. 26 U.S. Code 1031 – Exchange of Real Property Held for Productive Use or Investment California conforms, so a properly structured exchange defers both federal and state tax. Only real property held for business or investment qualifies. Your personal residence does not.
The timing is unforgiving. From the day you close on the sale of the relinquished property, you have 45 days to identify replacement properties in writing. The exchange must close within 180 days of that sale, or by the due date of your return for that year (including extensions) if that comes first.3Office of the Law Revision Counsel. 26 U.S. Code 1031 – Exchange of Real Property Held for Productive Use or Investment Miss either deadline and the deferred gain becomes taxable. There is no grace period.
California’s Form 3840 Follows You Out of State
If you sell California real estate and exchange into property located outside the state, you must file Form FTB 3840 with your California return for the year of the exchange and every subsequent year until the deferred gain is recognized.4Franchise Tax Board. Reporting Like-Kind Exchanges California is tracking the California-sourced gain so it can collect when the investment is eventually cashed out, even if you’ve moved to Texas or Florida by then.
Doing another 1031 exchange with the out-of-state replacement property does not end the filing obligation. It continues, potentially for decades, until the deferred gain is finally recognized on a taxable sale. Failing to file can trigger a proposed assessment for the entire deferred gain plus penalties and interest.4Franchise Tax Board. Reporting Like-Kind Exchanges Leaving the state does not leave this gain behind.
Qualified Small Business Stock: The Big California Gap
Federal law offers one of the most generous capital gains breaks on the books through Internal Revenue Code Section 1202. Stock acquired directly from a qualifying C corporation after September 27, 2010 and held more than five years can qualify for a 100% federal exclusion on gain, up to the greater of $10 million or ten times your adjusted basis.5Office of the Law Revision Counsel. 26 U.S. Code 1202 – Partial Exclusion for Gain from Certain Small Business Stock For founders and early employees of successful startups, this can shelter enormous gains from federal tax entirely.
California does not conform. The state never adopted Section 1202, and every dollar of QSBS gain is taxed as ordinary income on your California return. A $10 million QSBS sale that produces zero federal tax can still generate a California bill north of $1.3 million at the top rate. This is the single largest gap between federal and California capital gains treatment, and it is the reason many founders consider establishing residency elsewhere before a liquidity event. Whether that works depends on California’s residency and sourcing rules, which the Franchise Tax Board enforces aggressively.
Opportunity Zones and What California Won’t Follow
Opportunity Zones are designated low-income census tracts that carry federal tax incentives for long-term investment. Reinvest a capital gain into a Qualified Opportunity Fund within 180 days of realizing it and you defer the tax on the original gain.6Internal Revenue Service. Invest in a Qualified Opportunity Fund California conforms to the deferral, so both federal and state tax on the invested gain get pushed back.
The deferral runs until the earlier of two events: you sell the QOF investment, or December 31, 2026.7Internal Revenue Service. Opportunity Zones Frequently Asked Questions That date is now a hard wall. If you invested years ago and still hold the fund, the deferred gain becomes taxable on your 2026 return whether or not you’ve received any cash. Plan for the estimated tax payment accordingly.
The 10-Year Appreciation Exclusion Doesn’t Apply in California
The most powerful federal benefit of Opportunity Zone investing is what happens to the appreciation. Hold a QOF investment for at least 10 years and the federal government lets you step up basis to fair market value at sale, permanently excluding all growth in the investment from taxable income.7Internal Revenue Service. Opportunity Zones Frequently Asked Questions
California does not conform to the appreciation exclusion. The state allows the initial deferral but taxes the growth as ordinary income when you sell. For a QOF held long enough to produce substantial appreciation, you will owe California tax on gains that are completely exempt federally. Model that mismatch before committing capital to a QOF with a California return in mind.