High earners rarely get a single tax surprise. In 2026, three separate cliffs can hit at overlapping income levels, and trusts add a fourth. Understanding where they converge is the whole game for affluent families.
Trap 1: the NIIT at $200,000 / $250,000
The 3.8% Net Investment Income Tax kicks in at modified AGI of $200,000 (single) or $250,000 (joint), and the thresholds are not inflation-indexed. Dividends, capital gains, rents, and passive income all count. A family gliding just over the line pays 3.8% on every extra dollar of investment income.
Trap 2: the QBI cliff
For service-business owners, the 20% QBI deduction vanishes once taxable income passes about $276,800 (single) or $553,500 (joint). An SSTB owner earning $560,000 loses the entire deduction, which at the 37% bracket is worth roughly $40,000-plus of tax. A small income shift can preserve it.
Trap 3: AMT returning
The 2026 AMT exemption ($90,100 single / $140,200 joint) phases out starting at $500,000 / $1,000,000, and OBBBA restored the faster phase-out. Large SALT deductions under the new $40,400 cap and ISO exercises can pull a filer into AMT, where many deductions are added back.
Trap 4: trust compression
Estates and non-grantor trusts hit the top 37% federal rate, plus the 3.8% NIIT, at very low income: for 2026, taxable income above about $16,250. A trust holding a brokerage account can owe the top rate on a modest gain that an individual would barely notice. Funding and distributing from trusts needs explicit rate planning.
How they stack
A married couple with $600,000 of income that includes $200,000 of capital gains can, in one year, lose QBI (if SSTB), pay NIIT on the gains, and creep into AMT from large state-tax deductions. Each trap alone is manageable; together they can add five or six figures of tax.
Planning moves
- Time realized gains around the NIIT threshold
- Use defined-benefit plans to pull SSTB income under the QBI phase-out
- Bunch SALT into the 2025-2029 window to manage AMT
- Review trust distributions so compressed trust rates do not quietly apply
Disclaimer: This article is general educational information, not tax, legal, or investment advice. Dollar amounts come from the 2026 sources listed at the end of this article and may change. Before you act, talk to a licensed CPA, EA, or tax attorney about your own situation.