AMT in 2026: who still hits it, and planning ISO exercises around it

Before 2018, the alternative minimum tax ambushed five million households a year, mostly for the crime of living in a high-tax state with a few kids. Post-TCJA (and with those parameters extended), the AMT population has collapsed to a few hundred thousand filers — but for one group it remains the dominant tax planning problem: employees exercising incentive stock options. If you hold ISOs, AMT isn't a trivia question; it's the difference between a tax-free exercise and a six-figure bill on paper gains you can't spend. The good news: for this population, AMT is almost perfectly plannable.

The parallel tax in one paragraph

AMT is a shadow calculation run alongside your regular tax. Start with taxable income, add back 'preference items' (state and local tax deductions, the ISO exercise spread, certain other items), subtract a large exemption — roughly $89,000 single and $138,000 married filing jointly in 2026, phasing out at high incomes — and apply flat rates of 26% and 28% (the 28% bracket starting around $240,000 of AMT base). You pay whichever calculation is higher. Because regular rates top out at 37% while AMT tops at 28%, ordinary high earners with big salaries usually owe more under the regular system and never see AMT. The tax only bites when your regular tax is LOW relative to your economic income — which is precisely what an ISO exercise creates.

Who actually hits AMT now

The ISO mechanics

Exercising an ISO and holding the shares triggers no regular tax — that's the incentive. But the spread between fair market value at exercise and your strike price is added to AMT income in full. Exercise 20,000 options at a $2 strike when the 409A value is $22, and you've created $400,000 of AMT income while receiving zero cash. If you later sell after the qualifying period (two years from grant, one from exercise), the whole gain is long-term capital gains under the regular system — and you recover much of the AMT paid via the AMT credit in future years. The structure rewards those who plan across multiple years and punishes those who exercise everything at once.

Finding your crossover point

1. 1
   Compute regular tax as usual

   Project this year's return without any exercise — salary, deductions, the works.

2. 2
   Compute tentative AMT at zero spread

   Add back SALT, apply the exemption and 26/28% rates. For most W-2 households, this lands well below regular tax — the gap is your headroom.

3. 3
   Divide the gap by ~26-28%

   That's roughly how much ISO spread you can absorb before AMT overtakes regular tax. Every October-November, exercise up to that amount.

4. 4
   Re-run in December

   Bonuses, RSU vests, and updated 409A values move the crossover; true up with a final exercise before year-end if room remains.

Getting your AMT back: the credit

AMT paid on deferral items like ISO spreads generates a minimum tax credit (Form 8801) usable in future years when your regular tax exceeds tentative AMT. The catch: you recover it only as fast as that annual gap allows. A $105,000 AMT bill against a $10,000 annual regular-over-AMT gap takes a decade to recover — interest-free loan to Treasury. Selling the ISO shares helps twice: the sale year usually has high regular tax (accelerating credit usage), and your AMT basis in the shares is higher than regular basis, so AMT gain is smaller — a dual-basis adjustment preparers routinely miss. Track both bases yourself, forever.

The rest of the 2026 AMT map

• SALT: the deduction cap structure keeps most high-tax-state W-2 filers out of AMT; the classic pre-2018 trigger is largely defused, though large SALT deductions combined with big capital gains can still tip the calculation.
• Exemption phaseout: above roughly $626,000 single / $1,252,000 joint of AMT income, the exemption erodes at 25 cents per dollar, creating an effective 32.5-35% marginal AMT zone — relevant when sizing very large exercises or gains.
• Capital gains are taxed at the same preferential rates under AMT, but they consume exemption via the phaseout — a $500,000 gain year is a bad year to also exercise ISOs.
• Private activity bond interest remains an AMT preference: check whether your muni fund is 'AMT-free' if you have any exposure to the calculation.
• NSOs never trigger AMT — their spread is ordinary income under both systems, which is exactly why they're simpler and less valuable.

The bottom line

In 2026, AMT is no longer a middle-class ambush; it's a specialist tax that mostly prices one transaction — the ISO exercise-and-hold. Treat it accordingly: compute your crossover headroom every fall, exercise in annual slices that stay under it, prefer January to December, keep dual basis records, and harvest the AMT credit on the way out. Holders who run this playbook get long-term capital gains treatment nearly AMT-free; holders who exercise everything in one December learn what the tax was designed to catch.