ISO Cashless Exercise 2027 Tax Calculator
A 'cashless exercise' of ISOs — selling enough shares immediately to cover the strike price — is convenient but legally creates a disqualifying disposition. The bargain element becomes ordinary W-2 income (not capital gains), eliminating the AMT trap but also the favorable long-term tax rate.
| Bargain Element (ordinary income) | — |
| Shares Sold to Cover Strike | — |
| Shares You Keep | — |
| Broker / Cashless Exercise Fees | — |
| Federal + State + FICA Tax | — |
| Net Cash + Retained Share Value | — |
| Net Shares Retained | — |
Cashless exercise — selling exercised ISO shares the same day to fund the strike price — automatically triggers a disqualifying disposition under IRC Section 421(b). The bargain element converts from a potential long-term capital gain to immediate ordinary W-2 income. This eliminates the AMT cash trap but typically costs 8-15% more in total tax than an exercise-and-hold strategy.
Why Cashless Exercise = Disqualifying Disposition
An ISO qualifying disposition requires holding the shares 2 years from grant date AND 1 year from exercise date. A cashless exercise sells the same day as exercise — failing both requirements. The IRS treats the bargain element as ordinary income on Form W-2, subject to federal income tax, FICA (Social Security up to base, Medicare 1.45% + 0.9% additional), and state. No AMT preference because there is no holding.
When Cashless Exercise Makes Sense
Three good cases: (1) you cannot fund the AMT cash burden of exercise-and-hold, (2) you don't trust the company will survive — locking in liquidity matters more than tax efficiency, (3) you're terminating and have only 90 days to exercise. In all three cases, cashless exercise is rational despite the higher lifetime tax.
Sell-to-Cover vs Full Cashless vs Exercise-and-Hold
Sell-to-cover: sell ONLY enough shares to cover strike price + tax, retain rest. Full cashless: sell ALL exercised shares, take net cash. Exercise-and-hold: pay full strike from your own cash, hold all shares for qualifying disposition treatment. Tax cost roughly: full cashless > sell-to-cover > exercise-and-hold.
Last updated May 2026. Sources: IRS Form 3921 ISO Exercise, IRS Pub 525 Disqualifying Disposition Rules