How ESPP shares are taxed

How an ESPP works

An employee stock purchase plan lets you buy your employer's stock through payroll deductions. Most plans that offer a discount are "qualified" plans under Section 423 of the tax code, which is what this guide covers. You pick a contribution, often 1% to 15% of pay (the cap is set by the plan, not the law). The money builds up during an offering period, commonly 6 to 24 months, and on each purchase date the plan uses it to buy shares for you.

Section 423 allows a price as low as 15% below market. Many plans add a lookback: the discount applies to the lower of the price on the first day of the offering (the offering or grant date) and the price on the purchase date.

The discount and the lookback, in numbers

Say you earn $150,000 and contribute 10% to a 6-month offering that starts January 1, 2026, at $50 a share. That is $7,500 by the Jul 1, 2026 purchase. Here is what it buys if the stock rises to $60, with and without a lookback, and if it falls to $45:

Plans buy whole shares; the leftover cash is usually refunded or carried into the next purchase. Return on cost is the market value gained on the purchase date divided by what you paid.

A 15% discount sounds like 15%, but you pay 85 cents for each dollar of stock, so the instant gain on your money is 15/85, or 17.6%. With a lookback and a rising price the gain is much bigger: 41.2% here, because the $60 stock is bought at 85% of the old $50 price. When the price falls, the lookback cannot help, and you get the plain 17.6% on the lower price.

The $25,000 limit. You cannot buy more than $25,000 of stock a year through Section 423 plans, valued at the offering-date price, not what you pay. At $50, that is 500 shares, which cost $21,250 at the discounted price. Someone earning $400,000 who contributes 15% would put in $30,000 in six months but could buy only 500 shares; plans refund the excess. Unused room can carry forward only within an offering that spans more than one calendar year.

Two kinds of sale

Buying the shares is not taxed. What you owe when you sell depends on whether the sale is qualifying: more than 2 years after the offering date and more than 1 year after the purchase date. For the Jul 1, 2026 purchase, the first qualifying day is Jan 2, 2028.

• Disqualifying sale (sold sooner). The spread on the purchase date, market price minus price paid, is ordinary income: $3,080 on the 176 shares. That holds even if the price falls afterward. Sell in December at $48 and the $3,080 is still ordinary income, with a separate $2,112 short-term capital loss. Your cost basis becomes the purchase-date price, $60.
• Qualifying sale. Ordinary income is the smaller of your actual gain and the 15% discount on the offering-date price ($7.50 a share, or $1,320 here). Sell at $72 and $1,320 is ordinary income while $3,872 is long-term capital gain. If you sell below what you paid, there is no ordinary income, just a capital loss.

Here is selling on the purchase date compared with holding until Jan 2, 2028 at three prices, for a single filer earning $150,000:

Federal and state tax the sale adds to a full return with the standard deduction, at 2026 rates. Profit is sale proceeds minus the $7,480.00 paid minus tax. California taxes capital gains as ordinary income.

At an unchanged price, qualifying turns $1,760 of the spread into long-term gain and saves $158 of federal tax. The break-even is about $58.94 in Texas and $58.81 in California: below that, selling on day one would have left more. In California the saving is federal only, since the state taxes both kinds of income the same. Meanwhile a 20% drop costs $1,605, about 10 times the tax saved. That is why many people sell at purchase and treat the discount as a bonus.

No withholding: covering the tax

Federal law requires no income tax withholding on ESPP income, and ESPP stock is excluded from Social Security and Medicare wages. Your employer should still add the ordinary income to box 1 of your W-2 (if it is missing, you report it as wages yourself), but nothing was taken out for it. Selling the example shares at purchase adds about $739 of federal tax that is due at filing.

• Form W-4, step 4(c): $739 over the 14 paychecks left after Jul 1, 2026 is about $52.80 extra a check. See how to adjust your W-4.
• Estimated tax payments to the IRS by the quarterly due dates.

You generally avoid an underpayment penalty if withholding and timely payments cover 90% of this year's tax or 100% of last year's (110% if last year's adjusted gross income was over $150,000), or if you owe less than $1,000.

Form 3922 and the 1099-B basis mistake

By January 31 of the year after you buy shares, your employer sends Form 3922 for that purchase. It records the offering date, the purchase date, the market price on each, the price you paid and the number of shares. With a lookback, box 8 shows the price as if bought on the offering date. You do not file it, but keep it: it is how you work out the ordinary income and your true basis.

When you sell, the broker's 1099-B usually shows only the price you paid as your basis, because for options granted after 2013 brokers are not allowed to add the income taxed as pay. For the sale at purchase, that is $7,480, not the correct $10,560. Filed as is, the $3,080 discount already on your W-2 is taxed again as a short-term gain: about $1,026 of extra federal and California tax in this example.

The fix is on Form 8949: report the basis from the 1099-B in column (e), enter code B in column (f), and a negative adjustment of $3,080 in column (g). Many brokers send a supplemental statement with the adjusted basis. The same problem affects RSUs; see how RSUs are taxed.

Concentration risk

Your paycheck already depends on your employer. Holding ESPP shares for two years, on top of any RSUs, ties more of your savings to the same company. FINRA notes that some experts suggest no more than 10% of investment assets in one stock. If you also receive stock awards, the RSU calculator shows how much they add each year.