By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.
A qualified (Section 423) ESPP is taxed when you sell the shares, not when you buy them. If you sell within two years of the offering start date or within one year of the purchase date, the full discount you received at purchase is taxed as wages and any further gain or loss is a capital gain or loss. If you hold past both dates, usually a smaller slice is taxed as wages and the rest becomes long-term capital gain, which for 2026 is taxed at up to 20% federally (plus the 3.8% Net Investment Income Tax at these incomes) instead of up to 37%.
For a two-earner household earning $750,000 to $3 million, the discount is real money, but it is not where most of the tax is lost. The larger leaks are a cost basis on Form 1099-B that leaves out the income already on your W-2, nothing withheld when you sell, and holding a concentrated position for a federal saving that California does not match. This guide walks through each with numbers.
How a Section 423 ESPP works: the discount and the lookback
You choose a payroll deduction, usually a percentage of salary. The money comes out of after-tax pay, so it does not lower your W-2 wages. At the end of each purchase period, the plan buys company stock with what you have saved. Three rules in the Internal Revenue Code shape every qualified plan (IRC Section 423):
- Discount of up to 15%. The purchase price can be no lower than 85% of the stock’s fair market value on the offering (grant) date or on the purchase date, whichever is lower (Section 423(b)(6)).
- The lookback. Plans that use the lower of the two prices give you a “lookback.” If the stock rose during the offering period, you buy at 85% of the older, lower price, so your instant gain can be well above 15%.
- The $25,000 cap. Your right to buy may not accrue at more than $25,000 of stock per calendar year, measured at the grant-date fair market value, not the discounted price you pay (Section 423(b)(8)). At a 15% discount with no price change, that is about $21,250 of payroll deductions a year (85% x $25,000).
Under Section 423(b)(7), an offering with a lookback can last up to 27 months (up to five years if the price is set only from the purchase-date value); many plans use shorter periods with one or two purchases a year. Check your plan document for the exact terms, because the discount, lookback and purchase dates vary by employer. If your plan is not a Section 423 plan, the discount is generally taxed as wages at purchase, and none of the holding-period rules below apply. For a quick primer on why contributions are after-tax, see Is an ESPP pre-tax or post-tax?
Qualifying vs disqualifying dispositions: what is taxed as wages
Buying the shares is not a taxable event. The tax depends on when you sell (IRS Publication 525, Employee stock purchase plan).
Disqualifying disposition (sold early)
You sold within two years of the grant date or within one year of the purchase date. Your ordinary income is the stock’s value on the purchase date minus the price you paid. That amount is wages even if the stock later fell and you sold at a loss. Your basis rises by that income, and anything above or below the new basis is a capital gain or loss, short-term or long-term depending on how long you held after purchase.
Qualifying disposition (held past both dates)
You sold more than two years after the grant date and more than one year after the purchase date. Your ordinary income is the lesser of (a) the discount measured at the grant date, figured as if you had bought on the grant date, which in a 15% lookback plan is 15% of the grant-date price, or (b) your actual gain (sale price minus price paid) (IRC Section 423(c)). Because part (a) is measured at the grant date, it can occasionally exceed the wage amount of an early sale, for example when the stock fell between the grant and the purchase. The rest of the gain is long-term capital gain. If you sell at a loss, there is no ordinary income at all, just a capital loss.
What is not taken out of your pay
ESPP income from either kind of sale is not subject to Social Security or Medicare tax (IRC Section 3121(a)(22)), and your employer is not required to withhold federal income tax on it (IRC Section 421(b) for early sales, Section 423(c) for qualifying sales). That FICA saving is a quiet advantage over RSUs. The cost is that nothing is set aside for April, so the full bill lands on your return. Your employer sends Form 3922 with the grant date, purchase date, prices and values you need to work out the split.
Worked example: a $900,000 California household
Assumptions (illustrative, not a recommendation): married filing jointly, $900,000 of W-2 income, roughly $850,000 of federal and California taxable income. One spouse works at a Cupertino tech company with a plan that has a 15% discount, a lookback and a six-month offering. The stock is $200 on the offering date and $240 on the purchase date, so the price is $170 (85% of $200). They buy 125 shares, the most the $25,000 rule allows in a year at a $200 grant price ($25,000 / $200), for $21,250 of payroll deductions.
Rates used: federal 37% on ordinary income (the 2026 joint 37% bracket starts at $768,700 of taxable income, Rev. Proc. 2025-32); 20% on long-term gains above $613,700 for 2026; the 3.8% Net Investment Income Tax on capital gains (joint threshold $250,000, which applies to capital gains, not the wage part); California 10.3% on everything, from the 2025 joint schedule ($742,958 to $891,542, FTB), since 2026 California brackets are not yet published. California has no lower rate for capital gains.
| Scenario (125 shares, bought at $170) | Wages (ordinary) | Capital gain | Federal tax | California tax | Kept after tax |
|---|---|---|---|---|---|
| A. Sell on purchase day at $240 (disqualifying) | $8,750 | $0 | $3,237.50 | $901.25 | $4,611.25 |
| B. Sell at $260 after 13 months, before the 2-year grant date (disqualifying, long-term) | $8,750 | $2,500 | $3,832.50 | $1,158.75 | $6,258.75 |
| C. Sell at $260 after both dates (qualifying) | $3,750 | $7,500 | $3,172.50 | $1,158.75 | $6,918.75 |
| D. Hold for qualifying, but the stock falls to $200 | $3,750 | $0 | $1,387.50 | $386.25 | $1,976.25 |
How to read it. Compare B and C: same sale price, and the only difference is the holding period. Qualifying saves $660 of federal tax ($3,832.50 minus $3,172.50) on about $11,250 of gain. California tax is identical in both, because California taxes wages and capital gains at the same rates. Then compare A and D: a fall from $240 to $200, about 17%, costs $2,635 of after-tax profit, four times the federal saving from qualifying. The tax benefit of holding is small and fixed. The price risk is open-ended, and for most of these families it sits on top of RSUs in the same stock.
The cost basis trap on Form 1099-B (the ESPP double tax)
For compensatory options granted after 2013, which includes ESPP purchase rights, the basis your broker reports on Form 1099-B does not include the amount you report as wages (Form 8949 instructions). In scenario A, the 1099-B shows a basis of $21,250 (what you paid) and proceeds of $30,000, so tax software shows an $8,750 short-term gain. The same $8,750 is already in your wages, usually in box 1 of your W-2.
If nobody fixes it, that $8,750 is taxed twice. At this household’s rates, the overpayment is about $4,471: $3,570 federal (37% plus 3.8%) and $901 California. With two purchases a year, the error repeats on every lot. The fix is on Form 8949: enter code B in column (f) and adjust the basis up by the wage amount, so the true basis is $30,000 and the gain is zero. The supplemental statement from your broker, or the Form 3922 data, gives you the adjusted figure. If your wage amount for a qualifying sale does not appear on your W-2, you still report it as wages. Our guide to avoiding double tax on ESPP shares walks through the form line by line, and the same basis issue affects RSU shares.
Sell immediately or hold for a qualifying disposition?
For most high-income W-2 families, selling at purchase is the default worth beating. Here is why.
- The return is locked in. With a 15% discount, selling the same day turns $85 into $100, a 17.6% gain on money that sat in payroll for a few months, before tax. With a lookback in a rising year, it is more.
- The federal saving from holding is modest. In the example, about $660 per $11,250 of gain. It comes only from moving part of the gain from 37% to 23.8%.
- Concentration is the bigger risk. An Apple or Gilead household often already holds a large share of its net worth in employer stock through RSUs. ESPP shares held for two years add to that.
- Holding can make sense when employer stock is a small part of net worth, you would buy the stock anyway, and you have a cash plan for the tax. Even then, set a sale date and a floor price in advance.
We cover the timing question in more depth in Should you sell ESPP shares immediately? and When can I sell ESPP shares?. If you hold both ESPP and RSU shares, which to sell first depends on basis and holding period lot by lot.
California vs Washington: how ESPP tax differs by state
If you live in California
California taxes ESPP wages and capital gains as ordinary income, at up to 13.3% (12.3% plus the 1% Behavioral Health Services Tax on taxable income over $1,000,000, 2025 rules, FTB Form 540 booklet). The qualifying-disposition benefit is federal only. In scenarios A to C, California takes $901 to $1,159 per lot whichever way you sell. That makes holding for a qualifying sale even harder to justify for a California family than for a Washington one.
If you live in Washington
Washington has no individual income tax for 2026 (WA DOR), so the wage part of an ESPP sale owes no Washington income tax. The same family in Seattle keeps $5,512.50 in scenario A, about $900 more than in California. A long-term gain from a qualifying sale (or scenario B) can fall under Washington’s 7% capital gains tax, but only on gains above the annual standard deduction, $278,000 for 2025 (latest published), so most ESPP lots on their own will not reach it (WA DOR capital gains tax). Two cautions for high earners: gains above $1,000,000 are taxed at 9.9%, and Washington has enacted a 9.9% income tax on individuals and joint filers with adjusted gross income over $1,000,000, starting January 1, 2028 (SB 6346), with details on how income is calculated still pending from the Department of Revenue. ESPP plans that run past 2027 should be modeled with that in mind.
ESPP decision checklist
- Find your plan’s discount, lookback rule, offering and purchase dates, and whether it is a Section 423 plan.
- Decide your contribution so you reach, but do not exceed, the $25,000 grant-value cap for the calendar year. Excess contributions are typically refunded, not invested.
- Add up employer stock across RSUs, ESPP and any options. If it is already a large share of net worth, plan to sell ESPP shares at purchase.
- If you hold, write down the qualifying date (2 years from grant and 1 year from purchase) and a price at which you sell anyway.
- Set aside cash for the tax on each sale, since none is withheld. At these incomes, a rough figure is 37% federal plus your California rate on the wage part.
- Save every Form 3922 and broker supplemental statement. At tax time, check that every ESPP sale on Form 8949 has a code B adjustment where the wage amount is missing from basis.
- Review the plan once a year when open enrollment comes around, together with your RSU vest schedule.
What to document for your kids
Your children will not remember the purchase periods. What they can learn from is how you decided: why you joined the plan, why you sold on purchase day (or held), what share of the family’s net worth you were willing to keep in one company, and what you did with the proceeds. A short note each year, two or three paragraphs filed with the year’s Form 3922, becomes part of the FamilyKnowledge® Library that Age Five Family Office™ families keep for their children to read at 18. As Kevin Luu puts it, “Your kids don’t need to inherit your portfolio. They need to inherit your decision-making process.”
Questions families ask about ESPP taxes
Are ESPP shares taxed when I buy them?
Not in a Section 423 plan. Buying the shares creates no taxable income, even if you bought at a 15% discount with a lookback. The discount and any gain are taxed in the year you sell or otherwise dispose of the shares. How much counts as wages depends on whether the sale is qualifying or disqualifying. A gift of the shares counts as a disposition (IRC Section 424(c)), though a transfer to your spouse does not, so check the rules before transferring shares to a family member or a trust.
Does the $25,000 ESPP limit change for 2026?
No. The $25,000 limit is set in the statute and is not adjusted for inflation. It caps the stock you can buy per calendar year at its grant-date value, not your payroll deductions. At a 15% discount, that works out to about $21,250 of deductions if the price does not change. Each spouse with access to a plan has a separate limit.
What happens if I sell ESPP shares at a loss?
In a disqualifying sale, you still report the purchase-date discount as wages, and your capital loss is the sale price minus the purchase-date value, because your basis includes the wage income. That loss is larger than the one your 1099-B implies by the full wage amount. In a qualifying sale at a loss, there is no wage income at all, only a capital loss. In both cases, make sure the 1099-B basis is adjusted so the loss is not understated.
Next step
Pull your most recent Form 3922 and last year’s Form 8949 and check that every ESPP sale shows the adjusted basis. Our equity compensation page shows how ESPP, RSU and option decisions fit together, and the Tax & Wealth Assessment is there if you want a second set of eyes on your numbers. This is general education, and the right move depends on your family’s full picture.