Exercising ISOs After a Layoff: The Cheap Year Is Usually Out of Reach.

A staff engineer gets the call on November 13. Severance runs twelve weeks, the badge stops working Friday, and buried in the packet is a line about 15,000 vested incentive stock options at a $3.00 strike against a $15.00 share price. The question isn't whether to exercise. It's which calendar year to do it in, because exercising ISOs after a layoff is one of the few places a ten-week delay is worth $9,714.

Two rules do the work. Under §421(a) you recognize no regular taxable income when you exercise an ISO and hold the shares, so the spread never reaches your adjusted gross income. Under §56(b)(3) that same spread is an adjustment in computing alternative minimum taxable income, reported on Form 6251, line 2i, in the year your rights in the stock become transferable or stop being subject to a substantial risk of forfeiture.

The AMT you pay is the amount by which your tentative minimum tax (what the AMT system computes on its own) exceeds your regular tax, and salary moves both halves of that subtraction in opposite directions. It raises the regular tax, which is the credit against the tentative minimum tax. It also sits underneath the spread inside AMTI and pushes more of that spread out of the 26% rate and into the 28% rate, which for 2026 begins at $244,500 of taxable excess. In a year with a paycheck, the second effect wins. Above $500,000 of AMTI a second cliff opens, where the $90,100 exemption disappears at 50 cents on the dollar, and how many ISOs you can exercise without AMT prices that band.

§422(a)(2) requires that you be an employee of the granting corporation at all times from the date of grant through the day three months before exercise. Miss it and the spread is ordinary wage income in the year you exercise, with withholding and payroll tax on top. §422(c)(6) stretches the window to twelve months for a disability separation, and death has no limit. Nothing else does, so the cheap year isn't a planning choice. It's a function of the month you were let go.

• –Last day between January and September. The three-month window closes inside the same year your salary and severance landed, so the cheap year is unreachable as an ISO.
• –Last day between October and December. The window crosses January 1, and this is the only configuration where the empty year and the ISO clock overlap.
• –An extended post-termination window of seven or ten years. Useful for cash flow, irrelevant here. The plan can hold the option open, but it cannot keep it an ISO, because §422(a)(2) is statutory.

The gap year has one set of empty brackets and two good uses for them. Most of what gets written about low-income years is about the other one, converting traditional retirement money to Roth. Both moves want the same year, only one is visible to the health insurance marketplace, and almost nobody notices which.

Household income under §36B(d)(2)(B) is modified adjusted gross income, which adds back only excluded foreign earned income, tax-exempt interest, and the nontaxable part of Social Security. An AMT adjustment is not on that list and never reaches AGI. A $180,000 ISO exercise moves your premium tax credit by zero dollars. A Roth conversion moves it by every dollar converted.

That matters more in 2026 than it has in five years. The enhanced subsidies expired at the end of 2025, so the 400% poverty-line ceiling is back, which for one person on 2026 coverage is $62,600 of household income. One dollar past it and the credit is zero. Section 71305 of the One Big Beautiful Bill Act then repealed the repayment caps in §36B(f)(2)(B), so the whole year of advance payments comes back instead of stopping at $1,625. Excess premium tax credit repayment in 2026 has the rest of it.

One exception runs the other way. §56(b)(3) requires no adjustment if you dispose of the stock in the same year you exercise. Sell inside the calendar year and the AMT item vanishes, but the disqualifying disposition puts the spread in Box 1 of a W-2 and in AGI, where §36B can see all of it. Exercise and hold is invisible to the marketplace. Exercise and sell is not.

The number worth knowing is not the tax on the whole grant. It's how much spread you can run through before any AMT starts. On $275,000 of income that crossover sits at $43,500, which is 3,625 of these options. On $20,000 of unemployment it sits at $71,600, which is 5,966. The empty year does not shave a few percent off the bill. It gives you 65% more free room.

So if your last day falls in the fourth quarter, wait. Ten weeks for $9,714 is the best-paid stretch of the whole layoff, and the only cost is a calendar reminder. If your last day was in March, the cheap year is gone, and the honest answer is usually to exercise less than you planned, or nothing. Funding a $37,898 AMT bill out of severance you may need for rent, to buy more stock in the company that just laid you off, isn't a tax strategy.

The AMT does come back. It's a §53 minimum tax credit claimed on Form 8801, and I walked the recovery in the AMT credit for an ISO exercise. What people underestimate is the wait, because the credit releases only in a year when regular tax exceeds tentative minimum tax, which means a year when you're employed again. The rest of that separation packet is in what happens to your RSUs when you are laid off.