Do I owe tax on my ESPP shares in the year I buy them?

No. A §423 plan is a statutory plan, and §421(a) keeps the purchase out of income entirely, so a purchase with no sale produces no tax. Your employer sends Form 3922 by January 31 of the following year showing the offering date, the purchase date, both fair market values, and the price you paid. That form is an information statement under §6039, not a tax bill. Keep it, because those are the numbers the return needs years later.

How much can I put into an ESPP in 2026?

The statutory ceiling is $25,000 of stock per calendar year measured at the offering-date price under §423(b)(8), which is not the same as $25,000 of payroll deductions. At a $40 offering price with a 15% lookback discount, that is 625 shares costing $21,250 in cash. Plans usually add their own cap, often 15% of pay, and the lower of the two controls. The $25,000 figure is not indexed, so it covers fewer shares each year a stock rises.

Will selling my ESPP shares right away get me audited?

No. A disqualifying disposition is ordinary and expected, and it is reported by design: the discount shows up in Box 1 of your W-2 and the sale shows up on Form 1099-B. What actually draws a CP2000 is a 1099-B the IRS cannot match to anything on your return. The quieter risk runs the other way, since reporting the sale with the broker's understated basis taxes the same dollars twice and never generates a notice telling you so.

What happens to my ESPP if I quit in the middle of an offering period?

Most plans cancel your participation and refund the accumulated payroll deductions in cash, and there is no tax on that refund because the money was already taxed as wages. Plans are built that way because §423(a)(2) requires you to be an employee from the grant date until three months before the purchase for the shares to keep §423 treatment. Shares you already bought keep their holding periods and their tax treatment after you leave.

Is the ESPP discount subject to Social Security and Medicare tax?

No. §3121(a)(22) excludes stock transferred under a §423 plan, and any later disposition of that stock, from FICA wages, and §3306(b)(19) does the same for federal unemployment tax. That makes the ESPP discount the only compensation in a normal pay package that never touches payroll tax. It also means no federal income tax gets withheld on it under §421(b), so the tax has to come out of your own withholding or an estimated payment.

The Journal / Equity Compensation

How ESPP Is Taxed: Nothing at Purchase, Everything at Sale.

By Ewan Morkel, EAOctober 30, 20267 min read

Buying the shares is not a taxable event. The discount turns into wage income in the year you sell, and on a maxed 2026 plan the gap between selling at purchase and holding for the qualifying disposition is $825 of federal tax against $31,250 of single-stock risk.

Financial charts displayed on a laptop beside printed analysis

A software engineer at a public company opens the benefits portal in November, finds the box asking what percentage of each paycheck should go to the employee stock purchase plan next year, and picks a number out of the air. The plan buys at a 15% discount with a lookback, so the money really is close to free. The question the form never answers is how ESPP is taxed, and the answer decides two things: what percentage belongs in that box, and whether you owe the IRS a few thousand dollars in April that nobody withheld.

What you are actually buying

A 15% discount and a lookback are two different features.

IRC §423 sets the floor on the purchase price at 85% of fair market value, and §423(b)(6) lets the plan measure that 85% at the offering date, at the purchase date, or at the lower of the two. The last version is the lookback, and it's the whole ballgame. If the stock opens the offering period at $40 and closes it at $50, you pay 85% of $40, which is $34 for a share worth $50. That's a 32% discount off the purchase-date price, not 15%. A plan written that way has to close its offering inside the 27-month window in §423(b)(7), which is why most lookback plans run 6, 12, or 24 months and no longer.

The two clocks

How ESPP is taxed comes down to the date you sell.

§423(a)(1) wants the sale to happen more than two years after the offering date and more than one year after the purchase date. Clear both and you have a qualifying disposition. Miss either and you have a disqualifying one, which is how most ESPP shares are sold and is not a mistake by itself.

On a disqualifying disposition, §421(b) makes the spread at purchase, meaning fair market value on the purchase date minus what you paid, ordinary compensation income in the year of the sale. That number is locked in at purchase and does not shrink if the stock falls afterward. On a qualifying disposition, §423(c) taxes the lesser of your actual gain or the discount measured at the offering date, and the statute adds that where the option price is not fixed at grant it is determined as if the option had been exercised at that moment. For a lookback plan that works out to 15% of the offering-date price. Treas. Reg. §1.423-2 works the same example at a $100 share and a $90 deemed price. Everything above that ordinary piece is long-term capital gain.

Worked example: a maxed 2026 ESPP, sold two ways.

FMV at the offering date, January 2, 2026: $40.00
FMV at the purchase date, December 31, 2026: $50.00
Purchase price, 85% of the lower price: $34.00
Shares the §423(b)(8) cap allows for 2026: 625
Payroll deductions for the year: $21,250
Market value of the shares at purchase: $31,250
Discount built in at purchase: $10,000
Sell at purchase: ordinary income on the W-2: $10,000
Sell at purchase: federal tax at 32%: $3,200
Hold to January 3, 2028 at $50: ordinary income: $3,750
Hold to January 3, 2028 at $50: long-term gain: $6,250
Hold: federal tax at 32%, 15%, and 3.8%: $2,375
Federal tax saved by beating both clocks: $825
Single-stock risk carried 12 months to get it: $31,250

Tax year 2026 rates under Rev. Proc. 2025-32 for a single filer with $240,000 of salary, taxable income inside the 32% bracket that runs from $201,775 to $256,225, long-term gain in the 15% band below $545,500, and the 3.8% §1411 tax applying because modified AGI exceeds $200,000. The holding branch assumes the price is flat at $50 on January 3, 2028 and the same brackets in that year. Utah's 4.45% rate under S.B. 60 costs $445 on either path, before the taxpayer tax credit phase-out, because Utah taxes capital gain as ordinary income. The break-even is federal only: holding beats selling at $50 and paying the tax as long as the price stays above $48.37, with the cash from the early sale assumed to earn nothing.

The ceiling is the number most people get wrong. §423(b)(8) caps what an employee can accrue the right to buy at "$25,000 of fair market value of such stock (determined at the time such option is granted) for each calendar year in which such option is outstanding at any time." Grant date, not purchase date. At a $40 offering price that's 625 shares, and 625 shares at $34 costs $21,250, which is 8.9% of a $240,000 salary. Elect 15% and the plan either stops your deductions partway through the year or hands the extra back in cash, after borrowing it from you interest-free. The $25,000 is statutory and is not indexed for inflation, so it buys fewer shares every year the stock goes up.

Nobody withholds for this

The one piece of your pay that never touches payroll tax.

§3121(a)(22) keeps stock transferred under a §423 plan, and any later disposition of it, out of Social Security and Medicare wages, and §3306(b)(19) does the same for federal unemployment tax. The $10,000 above carries no payroll tax at all. The same $10,000 paid as an RSU vest would cost this filer $235 in Medicare and additional Medicare tax, with Social Security already capped out at the $184,500 wage base for 2026.

The catch comes attached. §421(b) says no amount has to be deducted and withheld under chapter 24 on that income, and IRS Notice 2002-47 is where the IRS said it would not press the point. So the $10,000 lands in Box 1 of the W-2 with nothing withheld against it, and the $3,200 of federal tax is yours to fund. Two maxed years back to back is a $6,400 hole. If your withholding isn't already covering 110% of last year's total tax, run the safe harbor calculator and fix it with a fourth-quarter estimate before §6654 adds an underpayment charge on top of it.

One more piece of mechanics, because it's the most expensive error I see on tech returns. The Form 1099-B your broker files will report basis of $21,250, the cash you paid, not the $31,250 that is your real basis once the $10,000 of W-2 income is added to it. Import that straight into software and you pay tax on the same $10,000 twice. The fix is one adjustment on Form 8949, and the ESPP cost basis post walks through it line by line.

Where I land

Sell at the purchase date unless you can name the risk you're carrying.

Max the plan, sell on the purchase date, take the ordinary income. The hold is not free money, it's a bet: $825 of federal tax saved in exchange for twelve more months owning $31,250 of a single stock issued by the company that already pays your salary. The break-even says the price has to stay above $48.37 for that bet to pay. A 3.3% slide wipes out the entire benefit, and a bad quarter costs several multiples of it.

I'll change that answer when the facts change. If the position is small against your net worth, if you were planning to hold company stock anyway, and especially if a low-income year is coming, the qualifying disposition is real money: the ordinary piece stays at $3,750 while the capital gain can land in the 0% bracket below $49,450 of taxable income for a single filer in 2026. What I won't do is hold a concentrated position to chase a tax rate. That's the same call as selling RSUs at vest, where the stock you keep ought to be a decision you made on purpose.