California Capital Gains Tax, Explained

The federal system rewards patience: hold an asset over a year and your rate drops to 0%, 15%, or 20%. California ignores all of it. Every dollar of gain — stock, crypto, a rental building, a business — lands on your CA return as ordinary income and climbs the same 1%-to-12.3% bracket ladder as your salary.

Two consequences follow. First, the state cost of a gain depends entirely on your total income for the year — a $200,000 gain on top of a $150,000 salary is taxed mostly in the 9.3% band, while the same gain for a $2M earner pays 13.3% on every dollar (the 12.3% top bracket plus the 1% Mental Health Services Tax that kicks in above $1 million of taxable income, gains included). Second, income timing is the whole game in California: spreading a gain across two tax years, or realizing it in a low-income year, does more work here than in almost any other state.

• QSBS (Section 1202): the federal code lets qualifying startup founders and early employees exclude up to $10M+ of gain. California conformity was eliminated years ago — the same sale that's federally tax-free can owe up to 13.3% to the FTB. Founders modeling an exit on QSBS math alone are missing a seven-figure line item.
• Opportunity Zones: no California deferral, no exclusion. An OZ rollover defers your federal bill; California collects in the year of the original sale.
• The long-term discount itself: as covered above — the single biggest "wait, what?" for new Californians and for anyone comparing after-tax outcomes across states.

A 1031 exchange defers California tax just like federal — until you exchange into property outside California. Then the FTB attaches a leash: Form FTB 3840, filed every single year, tracking the deferred California gain. Sell the Texas replacement property in 2035 and California collects its piece of the original gain, even if you've been a Texan for a decade. Miss the annual filing and the FTB can simply assess the deferred tax.

Selling California property also triggers real estate withholding — generally 3⅓% of the gross sales price (or an elective amount based on actual gain, via Form 593) held back at escrow. It's a prepayment, not an extra tax, but on a low-gain sale the default gross withholding can massively over-collect; the election is worth making before closing, not after.

And on every rental sale, the federal layer still applies: depreciation comes back at up to 25% federally as recapture — California just taxes it as more ordinary income.

The move-then-sell play is real, but narrower than the internet thinks. After a genuine residency change, gains from stock and most intangibles are sourced to your new state on the sale date — sell after you're a bona fide Nevadan and California generally has no claim. But three things stay stuck to California:

• California real estate — always California-source, forever, regardless of where you live.
• Installment payments from sales that happened while you were a resident — the character travels with the note.
• Deferred 1031 gains tracked on FTB 3840, as above.

• Year and bracket timing. Because CA has no long-term discount, the state bill is driven by which year the income lands in. Gap years, retirement years, and business-loss years are disproportionately valuable here.
• Installment sales. Conforms for CA — spreading a large gain keeps each year's slice out of the 12.3%/13.3% bands (and can hold you under the $1M MHST line year by year).
• Loss harvesting. Works dollar-for-dollar against gains on the CA return too, since it flows from federal AGI.
• Charitable stock gifts. Donating appreciated shares avoids both the federal and the full California tax on the gain — the 13.3% state layer makes this strategy meaningfully more valuable to Californians than to almost anyone else.
• 1031 within a plan — with the 3840 obligation modeled honestly if you're heading out of state.
• Residency change, done right — as a life decision executed well before a sale, not a tax trick executed the month of one.