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November 9, 2026

How Are Stock Options and RSUs Taxed? A Decision Map for ISOs, NSOs, RSUs and ESPP

Stock Option Strategy
How RSUs, NSOs, ISOs and ESPP are taxed in California in 2026.

By Glen Monroe, CFP®, Monroe Wealth Management. Reviewed 11/8/2026.

Federal figures are for 2026. California income tax rates are from the 2025 FTB schedules, the latest available as of October 2026.

Short answer

Each type of equity compensation is taxed at a different time: RSUs when they vest, NSOs when you exercise, and ISOs and ESPP shares when you sell, although ISOs can trigger the alternative minimum tax (AMT).

  • RSUs: the shares that vest, valued at that day's market price, are taxed as ordinary income.
  • NSOs: the spread (market value minus strike price) is taxed as ordinary income when you exercise.
  • ISOs: there's no regular income tax when you exercise, but the spread counts toward AMT.
  • ESPP: you aren't taxed when you buy. The discount you receive is taxed as ordinary income when you sell, and any further gain beyond the discount is taxed as a capital gain. California taxes all capital gains as ordinary income.

Who this is for

Tech employees based in California, whether at a pre-IPO startup or a publicly traded company, who hold any mix of ISOs, NSOs, RSUs and ESPP shares and want to know how each is taxed.

Key takeaways

  • What’s withheld isn’t always enough. Withholding is a prepayment, not your final tax. Employers withhold only 22% of RSU vests and NSO exercises (37% above $1 million in supplemental wages in a year), but the income is taxed at your actual tax bracket, which for higher earners is 32% or higher, so many owe more in April than what was withheld by your employer.
  • Exercising ISOs can trigger AMT (Alternative Minimum Tax). The 2026 AMT exemption is $90,100 for single filers and $140,200 for joint filers. It phases out at 50 cents per dollar of AMT income above $500,000 (single) or $1,000,000 (joint).
  • Holding NSOs for more than a year lowers your federal capital gains rate. NSOs sold within a year of acquiring them are taxed at ordinary rates, up to 37%. Held longer, gains are taxed at 15% for most high earners, and 20% for those above $545,500 of taxable income (single) or $613,700 (joint). A 3.8% net investment income tax can apply on top of that above $200,000 (single) or $250,000 (joint) of modified adjusted gross income. ISOs must be held for two years to receive a lower tax rate.
  • California doesn't reward holding longer. It taxes all gains as ordinary income, at rates up to 13.3%, whether you sell after a month or a decade. The state also sets a flat 10.23% for employers to withhold on stock compensation, which is a prepayment, not your final rate.
  • ESPP has its own clock. Selling more than 2 years after the offering date and 1 year after purchase can reduce how much of your gain is taxed as ordinary income. Any gain above the discount is long-term once you’ve held the shares a year.

How it works

Each type of equity is taxed at a different moment. The table shows when and the sections below explain how much.

Equity type At grant At vest or exercise At sale
RSUs (public company)No taxShares that vest × market price that day are taxed as ordinary income, plus payroll taxesGain above the vest-date value is taxed as capital gains
RSUs (pre-IPO)No taxNo tax as the time-based schedule vests. Tax applies when the IPO happens: shares that have met the time condition × market price that day are taxed as ordinary income, plus payroll taxesGain above the IPO-date value is taxed as capital gains. Sales are usually limited by a lockup period
NSOsNo taxSpread (market value minus strike price) is taxed as ordinary income, plus payroll taxesGain above the exercise-date value is taxed as capital gains
ISOsNo taxNo regular income tax; the spread counts toward AMT, or is taxed as ordinary income if you sell within one year of exercisingQualifying sale: any gain over the strike price is taxed as long-term capital gains. Disqualifying sale: spread is taxed as ordinary income
ESPPNo taxNo tax at purchaseDiscount is taxed as ordinary income for the first two years; the rest is taxed as capital gains

RSUs (restricted stock units)

RSUs for public companies are taxed when they vest. The amount added to your W-2 as wages is the number of shares that vest multiplied by the stock’s market price on the vest date, and both income and payroll taxes will apply. The stock price when the RSUs were granted isn’t what’s taxed.

Your employer withholds federal income tax at a flat 22% on supplemental wages up to $1 million in a year (you can opt into other withholding rates by filing a new W-4), and 37% on anything above that. To cover the withholding, many companies keep some of the shares that vest (called net-share settlement), so you receive fewer shares than vested. Others automatically sell enough of the vested shares on the vest date to cover the tax (sell-to-cover).

The 22% withholding rate is why tech employees often owe more in April than was withheld. In 2026, a single filer’s rate on taxable income reaches 32% above $201,775 and 35% above $256,225. Joint filers reach 32% at $403,550 and 35% at $512,450. Because your actual rate is higher than 22%, there is usually a gap between what your employer withholds and what you owe the IRS. Payroll taxes (Social Security and Medicare) are taken out on top of the 22% and generally aren’t part of that gap.

After vesting, your cost basis is the vest-date value. If you hold and the price rises, the gain is taxed as capital gains: short-term if you sell within a year, long-term if you hold beyond one year.

NSOs (non-qualified stock options)

NSOs are taxed when you exercise. The spread between the market value and your strike price is taxed as ordinary income, which is withheld and taxed exactly like an RSU vest. You choose when to exercise your NSOs and what year that income falls in.

At a private company, the market value is usually the most recent 409A valuation, which is an independent appraisal of the company’s common stock that’s typically refreshed at least once a year. Because that value sets your taxable spread, exercising can create a large tax bill on shares you can’t yet sell. 

If your plan allows early exercise, some employees exercise right after they’re hired when the spread is small, and file an 83(b) election within 30 days to be taxed on that spread up front. This means paying for shares up front, and if you leave before they vest, you may lose some or all of that money and the tax you paid.

Your cost basis is the market value on the exercise date, so only gains above that are taxed again when you sell, as short-term or long-term capital gains.

ISOs (incentive stock options)

ISOs offer the best potential tax treatment but carry the most complexity. Two moments matter most with this type of equity: when you exercise and when you sell.

At exercise, you don't owe regular income tax, but the spread (the stock's market value on the exercise date minus your strike price) counts toward the alternative minimum tax (AMT). AMT is a parallel federal calculation that applies to a broader measure of income, including the ISO spread. Each year, you owe whichever is greater: your regular income tax or your AMT.

At sale, how long you hold the shares decides how your gain is taxed. If you hold them for more than 2 years from the grant date and more than 1 year from exercise, the sale is a qualifying disposition, and your entire gain over the strike price is taxed at long-term capital gains rates. Selling them sooner results in a disqualifying disposition: the spread at exercise is taxed as ordinary income instead.

One limit: The first $100,000 of an ISO grant by a company (calculated using grant-date value) that become exercisable in a year qualify as ISOs. The rest are treated as NSOs.

ESPP (employee stock purchase plan)

An ESPP lets you buy company stock at up to a 15% discount, often based on the lowest stock price at the start or end of the offering period. You can buy up to $25,000 of stock a year, measured at the offering-date price. Nothing is taxed when you buy.

These rules apply to qualified ESPPs, which meet the requirements of IRC § 423 and are the type most employers offer. If your plan isn't qualified, the discount is typically taxed as ordinary income when you buy, so the holding periods below don't apply.

When you sell, the amount you owe in tax depends on how long you held the shares:

  • Qualifying disposition (more than 2 years from the offering date and more than 1 year from purchase): the part of your gain taxed as ordinary income is limited to the smaller of your actual gain or the discount calculated on the stock price at the offering date. Any remaining gain is taxed as long-term capital gain.
  • Disqualifying disposition (within 2 years of the offering date or within 1 year of purchase): the full discount at purchase is ordinary income, and any further gain or loss is capital.

Capital gains and the 3.8% investment income tax

Federal long-term capital gains rates in 2026 are 20% on taxable income above $545,500 (single) or $613,700 (joint). Higher earners also owe a 3.8% net investment income tax (NIIT) on investment income such as capital gains, once modified adjusted gross income exceeds $200,000 (single) or $250,000 (joint). Because wages aren’t investment income, the NIIT applies to the gain when you sell, not when RSUs vest or NSOs are exercised.

How California taxes your equity

  • No capital gains rate. California taxes long-term and short-term gains as ordinary income, at rates up to 13.3% (12.3% plus the 1% Behavioral Health Services Tax on income above $1 million). This is in addition to federal tax.
  • 10.23% withholding. California sets a flat 10.23% for employers to withhold on stock compensation, regardless of your bracket.
  • California AMT. ISO exercises can trigger California's own AMT, calculated separately from the federal one, at a 7% rate.
  • State disability insurance. California SDI is withheld at 1.3% on all wages in 2026, with no cap, so it applies to every RSU vest and NSO exercise.

The decisions you need to make for what you hold

Most people hold more than one type of equity, and what you do with one can change the tax you owe on the others. Find the combination that matches your equity portfolio.

RSUs only

Decision: whether to sell on the vesting date or hold longer term. Selling right after they vest creates little to no extra tax, because your basis equals or is very close to the sale price. Holding long term turns the shares into a stock investment, which will carry a capital gains tax if the stock increases in value above the vesting date price. Holding gives you the upside if the stock rises, but it concentrates your wealth in the company that also pays your salary. If the company struggles, your job and the gain on your shares are both at risk.

Our Take We treat an RSU vest like a cash bonus that happens to arrive in stock. If you wouldn't take that cash and buy your employer's shares with it, holding the shares is the same decision. That's a general rule, not advice for your situation: some people have good reasons to hold, such as a planned gift of appreciated shares.

Second decision: how to cover the shortfall between the 22% your employer withholds and the tax you actually owe at your bracket, often 32% or higher. Common approaches are raising the withholding on your paycheck with a new W-4, making quarterly estimated tax payments, or setting aside part of each vest in cash for the April tax bill.

RSUs + ESPP

Decision: when to sell ESPP shares around your RSU vest dates. Selling ESPP shares at a loss within 30 days before or after an RSU vest can trigger the wash-sale rule. The rule delays the tax benefit of the loss because the vested RSUs count as a repurchase of the same stock. Timing ESPP sales away from vest dates avoids this pitfall.

Our Take We generally see an ESPP as a savings tool with a built-in discount, not a long-term investment. Most of its value is captured the day you buy. Holding for a qualifying disposition only lowers the tax on the discount, which may not be worth a year or more of extra concentration. Whether it's worth it depends on your plan's terms and how much of your company's stock you already own.

ISOs + RSUs

Decision: how many ISOs to exercise each year without triggering AMT. Your RSU income raises both your income tax and your AMT income, which changes how many ISOs you can exercise before AMT applies. Many people consider exercising up to the point where their AMT and income tax obligations are equal, which is called the AMT crossover point.

The trade-off is timing. Exercising early in the year starts the one-year holding period sooner, but you commit before you know what that year’s full income looks like. Exercising in December lets you estimate AMT more accurately because you know what your income for the year will be, but it leaves less time before year-end to sell if the stock drops in value.

Our Take If the stock drops well below your exercise price before year-end, a sale in the same year (a disqualifying disposition) is often the better path. It turns the AMT bill on value you no longer have into ordinary income on the smaller amount you actually received. Whether that comes out ahead depends on your numbers, so it's worth running both before December 31.

NSOs + RSUs

Decision: which year to realize the NSO income. Both are taxed as ordinary income and are subject to payroll taxes. RSU vests arrive on a schedule you can’t change, but you choose when to exercise your NSOs, within your plan’s rules. Moving an exercise into a lower-income year, such as a year with fewer vests or a sabbatical, can keep more of that income out of the higher tax brackets.

Exercise timing also affects withholding. If your supplemental wages, such as RSU, NSO and bonus income, are greater than $1 million in a year, federal withholding on the amount above $1 million rises to 37%. Since the first $1 million is withheld at only 22%, there will be a shortfall between what your employer withholds and what you owe the IRS in April.

Options only (pre-IPO)

Decisions: whether to exercise before a liquidity event, and how much risk you want to take. Exercising early can start the holding period and lock in a lower spread. It also means paying the strike price, and possibly AMT or income tax, on shares you may not be able to sell for years. For a broader list of what to sort out before an IPO, see our Pre-IPO Checklist for Employees.

If you leave the company, most plans give you 90 days to exercise vested options. That deadline turns a planning decision into a forced one, so it pays to know what exercising would cost, including taxes, before you resign. We cover this in more detail in Managing Your Stock Options During a Career Transition.

Our Take Two general rules we use. First, if your strike price is higher than the current value of the shares (the options are "underwater"), exercising means paying more than the shares are worth, and we generally don't see a reason to do it. Second, at a private company, exercise only with money you could afford to lose entirely, because the shares may not become sellable, or may lose value before they do.

All four

With ISOs, NSOs, RSUs and ESPP, the order of your moves matters. Here is a decision tree you can consider if you hold all of these equity types:

  1. Map the year's RSU vests and ESPP purchases first, since you can't move them.
  2. Cover the withholding shortfall on that fixed income.
  3. Decide how many ISOs to exercise, up to the point where AMT would start to apply on top of that income.
  4. Place NSO exercises in the lowest-income year available.
  5. Decide which shares to sell and when, weighing the cost basis of each purchase.

Our Take Let taxes break the tie, not make the decision. We often see people hold too much company stock to avoid a tax bill, then lose more to a price drop than the tax would have cost. Many planners use a guideline of keeping any single stock below 10% of net worth. The right level for you depends on your income, timeline and other assets.

Common mistakes

Holding RSUs-only

In addition to market fluctuations, your company’s vesting schedule will also affect the value of the shares you receive on a given vesting date. Quarterly or annual vesting periods are the most common, where you receive the same percentage of outstanding shares each year/quarter. Some companies, Amazon in particular, use a back-loaded vesting schedule. Rather than receiving 25% of your RSU shares each year for 4 years, you receive only 5% of your Amazon RSU shares the first year, 15% the second year, and then 40% in each of the third and fourth years. If you haven’t taken the vesting schedule into consideration, you may find yourself expecting to have received more income in the first two years than you’ll actually be getting (market fluctuations notwithstanding).

Holding RSUs + ESPP

While participating in your company’s RSU plan typically requires no more than signing your grant document, participating in their ESPP requires proactive enrollment during what is called an offering period. Your company may have only limited offering periods in which you can enroll in the plan; if you miss this window, you will need to wait until the next one before you can participate. While these do not necessarily line up with your company’s open-enrollment period or the beginning of the calendar, your benefits department should have this information at their fingertips if you ask for it.

In addition, an ESPP is subject to the lower of two different limits: an annual purchase limit of $25K worth of stock (valued by the fair market value of the stock on the first day of the offering period), or a company-determined percentage of salary (usually 10% or 15%). If your income is high enough, it may make sense to contribute less than the plan’s maximum percentage. 

As an example, let’s assume someone with a salary of $300K works for a company whose ESPP limits contributions to 10% of one’s salary at a 15% discount relative to market price. Their offering period opens today, and their company’s stock is trading at a nice, round $100 per share. 

If this person were to contribute 10% of their salary to the ESPP, they would end up contributing $30K per year and may expect to receive stock in the amount of approximately $35.3K ($30K/85%) when accounting for the 15% discount. Recall, however, that one is limited to purchasing $25K worth of stock as of its value at the start of the offering period. In this case, the actual maximum amount of stock this employee could purchase would be $21,250 ($25K * 85%)--not $30k, and not $25K either! The employee would be made whole and refunded their excess contribution of $8,750, but those are funds that could have been better allocated in the meantime.

To calculate the optimal contribution percentage for this example, let’s assume this company has one offering period and that it is at the beginning of the year. The calculation would be as follows:

  • $25,000 IRS maximum * 15% plan discount = $3,750
  • Actual value of stock employee can purchase through ESPP: $25,000 - $3,750 = $21,250
  • $21,250 / $300,000 salary = 7.08%, which can be rounded up to 8% to ensure they max out their available contribution space.

Frequently asked questions

Can I ask my employer to pay me in extra cash instead of in employer stock?

You can try, but that’s generally not something they do. Some companies like Netflix and Amazon have offered arrangements like this in the past, but even these arrangements are often set up so that the employee is incentivized to choose the equity option. Think “we’ll give you $x in employer stock based on today’s market price, or we’ll pay you $.75x in cash, subject to the same vesting periods”.

Are employers incentivized to offer equity compensation instead of paying additional cash?

Yes, for at least two different reasons. The first is that the company may feel like equity compensation incentivizes employees to go above and beyond; after all, you now participate directly in the success of the company overall. The second has to do with the company’s cash flow: shares on paper that may be worth something at some point in the future don’t come out of their proverbial cash register the way paying cash bonuses today does, even if the company experiences a lucrative liquidity event. For an early-stage company still working to get its feet underneath it, this can be the difference between making it to a successful exit and running out of money.

Aren’t my taxes lower if I wait to sell until I’ve held my shares for over a year?

That depends on which tax jurisdiction one is talking about. On a federal level, yes; long-term capital gains rates are lower than the short-term capital gains rates for assets held for a year or less. Over on the California state tax side, however, capital gains are taxed the same regardless of whether they are short-term or long-term. If you live in a state other than California, that state’s tax code will dictate the amount you owe in employer-stock-related taxes.

Talk to Monroe Wealth Management

Every equity package interacts differently with your income, AMT and state taxes. If you'd like your own numbers modeled before your next vest, exercise or IPO, book a 30-minute call with us.

Coming next in The Equity Playbook

This is the first guide in The Equity Playbook, which discusses each combination of equity in depth, starting with what happens before an IPO. We will update the links here as they are published

  • Double-Trigger RSUs and NSOs Before an IPO: What Happens on IPO Day
  • ISOs + RSUs Before an IPO: The Exercise-and-Hold Sequence
  • Leaving a Startup? Your Options' 90-Day Window, and How to Weigh the New Offer's Equity
  • RSUs + ESPP: Qualifying Dispositions, Wash Sales and Your 1099-B
  • Should You Sell RSUs When They Vest? A Sell Plan for Public-Company Employees
  • 10b5-1 Plans for Tech Executives: Selling on a Schedule Without Timing the Market

Sources

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