Does California tax stock options exercised after a move out of state?

Two different rules for two different kinds of income

A compensatory nonqualified stock option produces two separate income events, and California sources them under two separate rules. The first event is exercise. Because the option was granted for services, the spread recognized at exercise, the fair market value of the stock on the exercise date minus what the employee paid to acquire it, is treated as wages. California's personal income tax reaches all the income of a resident regardless of where it was earned, and reaches only the California-source income of a nonresident or part-year resident (Rev. & Tax. Code section 17041(i)(1)). Section 17951(a) restates the same limit from the nonresident's side: a nonresident's gross income for California purposes "includes only the gross income from sources within this state." For compensation, "sources within this state" is defined by where the services were performed, not by the taxpayer's address on the day the income happens to be recognized.

The second event, if the employee keeps the stock rather than selling immediately, is whatever happens to the shares afterward. Once exercised, the shares are ordinary investment property, and their basis is the fair market value of the stock on the exercise date, which is the exercise price plus the spread already taken into income as wages (Treas. Reg. section 1.83-4(b)). Any change in value after that point, measured against that exercise-date figure rather than against what the employee wrote the check for, is capital gain or loss, not compensation. Gain on intangible personal property, stocks included, is governed by a different statute: Revenue and Taxation Code section 17952 excludes a nonresident's income from stocks, bonds, notes, or other intangible personal property from California-source income, unless the property has acquired a business situs in the state, or unless the nonresident buys or sells such property in California, or places orders with brokers in California, so regularly, systematically, and continuously as to constitute doing business here. Neither exception typically applies to an employee's own option shares. The practical result is that the exercise spread and the post-exercise appreciation are taxed, if at all, under two different theories, and a residency change in between can pull one into California's reach while leaving the other out.

The exercise-spread rule: sourced to the work, not to the address

The regulation the Franchise Tax Board relies on for allocating compensation between California and other states is Cal. Code Regs., tit. 18, section 17951-5, which requires that compensation for personal services performed partly within and partly outside California be apportioned so that only the portion "reasonably attributable to personal services performed in this state" is taxed here. FTB Publication 1004, Equity-Based Compensation Guidelines, applies that regulation specifically to stock options and translates it into a formula: for a nonqualified stock option exercised by a nonresident or part-year resident who performed services both inside and outside California, the California-source share of the spread equals California workdays divided by total workdays, counted from the option's grant date through its exercise date, or through the date employment with the granting company ended, whichever comes first.

That last clause matters more than it looks. It means the denominator does not keep running past the point the employee stopped working. A retiree who worked exclusively in California from grant until the day employment ended, then moved out of state and exercised the vested option months or years later, has a ratio of California workdays to total workdays of essentially 100 percent, because every workday in the measuring period, which stops at retirement, was spent in California. The later years spent living elsewhere, not working, do not dilute the fraction. That is the answer to the question this article asks: yes, the state where the option holder happens to live on exercise day is close to irrelevant; what controls is where the person was working while the option was being earned, and Publication 1004's own worked example shows the same mechanics with mixed facts, allocating 70 percent of the spread to California in an illustration built on 700 California workdays out of 1,000 total workdays between grant and the end of employment.

The case law runs the same direction. In Appeal of Stabile, 2020-OTA-198P, a designated precedential opinion of the Office of Tax Appeals, the taxpayer received long-term incentive shares while employed in California, relocated abroad, and had the shares vest and pay out roughly eight months after his California residency ended. The Office of Tax Appeals sustained the Franchise Tax Board's position that the payment was compensation for services and that a workday allocation covering the grant-to-vesting period, which produced a California-source share of 63.7 percent, nearly two-thirds of the payment, applied regardless of the taxpayer's nonresident status on the date the income was paid. An earlier FTB Chief Counsel Ruling, numbered 2013-02, reached a parallel conclusion for restricted stock units using the same grant-to-vest workday ratio; a Chief Counsel ruling is not precedential and is not citable as binding authority, but it is consistent, persuasive agency guidance on how the allocation runs in practice. Restricted stock and RSUs are sourced on essentially the same logic as nonqualified stock options under Publication 1004, with income recognized at vesting rather than exercise and the workday ratio measured from the award's purchase or grant date to the vesting date, or to the earlier date employment ended.

One qualification closes the loop: if the employee is once again a California resident on the exercise date, the allocation exercise is beside the point, because a resident is taxed on all income regardless of source (Rev. & Tax. Code section 17041, subdivision (a)(1)), and a part-year resident is taxed on all income received during the resident period (section 17041, subdivision (i)(1)(A)). The workday allocation only does work for someone who is a nonresident, or a part-year resident treated as such, at the moment the spread is recognized.

The later-sale rule: shares held past exercise are a different asset

Once the option has been exercised, the sourcing question resets. FTB Publication 1004 treats capital gain on shares sold after exercise as ordinary intangible-property gain under section 17952: California taxes that gain only if the taxpayer has become a California resident again by the time of sale. A taxpayer who exercised the option, held the resulting shares, moved out of state, and later sold the shares while still a nonresident recognizes no California-source gain on that sale, because the shares by that point are ordinary stock, sourced under the intangible-property rule rather than the compensation rule, and a nonresident's intangible-property gain is excluded from California income under section 17952 absent a business situs. What is being sourced in that second inquiry is only the movement in value after exercise, because the exercise-date fair market value became the basis in the shares; the portion of the eventual sale proceeds that represents the spread was already taxed once as wages and does not come back a second time as gain. The point cuts both ways, since a taxpayer who has resumed California residency by the sale date owes California tax on the post-exercise appreciation alone, not on the whole difference between the sale price and the exercise price. This is the split the question turns on: the exercise spread looks backward, to where the option was earned, while the post-exercise gain looks forward, to residency at the time of sale.

The audit reality: what a part-year return needs to show

A former employee who exercised a large option grant, or had a substantial RSU vesting, in the same calendar year as a claimed move out of California is a natural candidate for inquiry, because the W-2 or brokerage reporting for the exercise or vesting event sits next to a part-year or nonresident return claiming a mid-year residency change. Determining when that residency change occurred is its own inquiry, governed by California's presumptive residency framework: California weighs day counts and connections to the state and lets the whole record decide, with only a rebuttable statutory presumption for presence of more than nine months (Rev. & Tax. Code section 17016) and a narrow employment-contract safe harbor (section 17014, subdivision (d)), unlike states whose statutory residency tests combine a day count with a maintained home. But that residency determination is a distinct question from the sourcing question addressed here. Even a clean, well-documented, unchallenged move date does not change the exercise-spread allocation, because that allocation runs off workdays during the earning period, not off the residency change date. A recent illustration: after a December 2015 move to Nevada, restricted stock units that vested on December 31, 2015 for California services remained California-source income, while severance paid in 2016 for a release of claims did not (Appeal of Otting, 2026-OTA-403P, posted August 2026 and marked pending precedential, applying Appeal of McAneeley (80-SBE-131)). A part-year return still has to show the two calculations separately: the workday allocation that sources the exercise spread (or vesting income) to California regardless of the move, and the ordinary part-year split of everything else, wages earned after the move, interest, dividends, and any post-exercise capital gain, between the resident and nonresident portions of the year. That last item carries a trap of its own: capital gain on shares acquired by exercise runs from the exercise-date fair market value, so a return that computes it from the exercise price reports the spread a second time, now dressed as gain, after it has already been reported as wages. Getting the second calculation right does not fix an error in the first one, and an examiner comparing the reported wage or equity income against the total shown on the equity award statement will notice a gap.

Practice notes

The recurring mistake is treating the move date as the answer to the sourcing question, when it answers a different question. A taxpayer, or the taxpayer's return preparer, sees a clean, well-supported residency change and assumes a stock option exercised after that date is nonresident income; the workday allocation says otherwise whenever the earning period included California workdays, and it is not forgiving of a long gap between employment and exercise, since the denominator freezes at the earlier of exercise or termination rather than growing with time spent elsewhere. The corollary planning point cuts the other way: because the denominator is capped at the date employment ends, an employee who keeps working outside California after a partial relocation, rather than retiring outright, can shift the ratio meaningfully by extending the outside-California service period before exercising, a timing question that belongs in front of an exercise decision rather than after it. A proper equity-compensation review at the time of a residency change pulls the grant agreements, the vesting and exercise dates, and a workday log for every open grant, not just the ones exercised in the move year, since options exercised later still carry the earlier grant-to-exercise workday history. One mechanical trap belongs on the same checklist: brokers commonly report only the exercise price as the basis on Form 1099-B for shares acquired through an option exercise, so the return has to adjust the basis up to the exercise-date fair market value, or the spread already taxed as wages is taxed a second time as capital gain. Where the earning period spans multiple employers or an acquisition that reset vesting schedules, the calculation gets complicated quickly, and getting it wrong in either direction is a real cost. G&G State Tax Group provides equity compensation sourcing analysis for individuals who have left California alongside its state and local tax practice.