1. Get reacquainted with the alternative minimum tax (AMT)
Since the passing of the 2017 Tax Cuts and Jobs Act (TCJA), the AMT has been largely irrelevant for many high‑income households. The TCJA dramatically raised AMT exemption amounts and — just as importantly — pushed the phase‑out thresholds so high that even affluent taxpayers rarely crossed them. As a result, AMT planning faded from routine advisor workflows.
That changes for 2026, as a result of the OBBBA.
While the OBBBA permanently extends the higher AMT exemption amounts introduced under TCJA, it quietly rewinds the phase‑out mechanics to something much closer to pre‑2018 law. In other words, the exemption survives — but it evaporates far more quickly as income rises.
The result is not a return to universal AMT exposure but a renewed and very real risk for a familiar subset of clients — particularly in years when income is uneven, concentrated or accelerated.
Why AMT becomes a problem again in 2026
The AMT is a parallel tax system with a broader tax base and fewer allowable deductions. Taxpayers calculate their liability twice — once under the regular tax code and once under AMT rules — and pay whichever is higher. The “problem” arises not from AMT itself, but from how easily taxpayers fall into it.
Under the TCJA framework through 2025, AMT exemption amounts were high, and exemptions phased out slowly (at a 25% rate) and only at very high income levels.
Beginning in 2026 under the OBBBA, the higher exemption amounts remain, but phase‑out thresholds reset to $500,000 for single filers and $1,000,000 for married couples filing jointly, indexed thereafter. The phase‑out rate doubles to 50%.
Practically, that means each additional dollar of income above the threshold eliminates exemption value twice as fast as it did under TCJA. Clients who comfortably avoided AMT in previous tax years may find themselves squarely back in it — especially in “lumpy” income years.
“Our analysis suggests significantly more people will be paying AMT,” says Lauren Liebes, a wealth strategist at Capital Group. “Not because they suddenly became wealthier, but because the margin for error narrowed.”
Who has the highest AMT risk?
In 2026, AMT exposure risk will concentrate among clients with specific characteristics — many of whom have not needed active AMT planning in recent years:
- Clients in high‑tax states
State and local tax (SALT) deductions remain disallowed under AMT, making high earners in states like California, New York and New Jersey perennial candidates once phase‑outs accelerate. - Employees with incentive stock options (ISOs)
ISO exercises remain one of the most common AMT triggers. A single large exercise — especially when layered on top of already high W‑2 income — can wipe out the AMT exemption entirely. - Clients with large capital events
Business sales, concentrated stock liquidation or real estate gains can push income above the reset phase‑out thresholds in a single year, even if baseline income is otherwise manageable. - Investors with private‑activity municipal (muni) bond income
Interest from certain muni bonds is tax‑free for regular tax purposes but taxable under AMT, quietly increasing AMT income relative to adjusted gross income (AGI).
In short, this is not about “ultra high‑net‑worth” households only. It is about upper‑middle and upper‑income clients whose income arrives unevenly — and whose planning assumptions are still anchored to the TCJA era.
How advisors can help
The most important shift for advisors is not technical — it is procedural. AMT needs to move back into proactive planning, not post‑filing cleanup.
- Model AMT before the client makes the move. High earners should run AMT projections with their accountants. “AMT is not a back‑of‑the‑envelope calculation,” Liebes says. ISO exercises, large capital gain realizations and business liquidity events can create avoidable AMT surprises without projections.
- Plan in multiyear blocks, not single-year snapshots. Because AMT is highly sensitive to income concentration, spreading ISO exercises, gain recognition or deferred compensation payouts across multiple tax years can materially reduce exemption erosion and avoid AMT “spike” years.
- Treat SALT and other AMT add-backs as part of the plan. AMT income is frequently higher than AGI due to disallowed deductions and preference items. SALT, miscellaneous itemized deductions and private‑activity bond interest should be incorporated into projections — not treated as footnotes.
- Re‑educate clients who think AMT is “behind them.” Many clients mentally closed the book on AMT after 2018. Advisors should explicitly reset expectations: The rules changed again, and past experience is no longer a reliable guide.
The takeaway is straightforward: AMT is not universally punitive, but it is newly relevant. In 2026 and beyond, the risk lies less in marginal tax rates and more in exemption erosion — making timing, modeling and coordination more valuable than they’ve been in years.