2026 equity comp tax numbers: every rate, bracket, and limit in one place

If your pay includes equity, almost every tax decision comes down to a handful of numbers that change each year. This page collects the 2026 figures that matter for RSUs, ISOs, NSOs, and ESPP, each tied to the IRS source that sets it. Where a 2026 number is different from what you might expect, it is usually because of the One Big Beautiful Bill Act (OBBBA), which changed several parameters beyond the normal inflation adjustment — most importantly the Alternative Minimum Tax.

Federal income tax brackets (2026)

These are taxable-income thresholds — income after your standard or itemized deduction. A single filer does not reach the 37% bracket until $640,600 of taxable income.

Most equity-comp earners sit in the 24%, 32%, or 35% band, which is exactly why flat 22% supplemental withholding leaves a gap (see below).

Standard deduction (2026)

Alternative Minimum Tax (2026) — the big OBBBA change

AMT is its own parallel tax: you compute tentative minimum tax (26% on AMT income up to the breakpoint, 28% above) and pay the higher of that or your regular tax.

The ISO bargain element (fair market value minus strike, times shares) is the most common preference item that pushes tech workers into AMT.

Note the standard deduction is not allowed for AMT — it gets added back to AMT income — so even standard-deduction filers feel the calculation.

The practical effect of the OBBBA change: a single filer who exercises and holds ISOs now starts losing the $90,100 exemption at $500,000 of AMT income instead of around $640,000, and loses it twice as fast.

The exemption is fully gone by roughly $680,000 of AMT income (single) — at $500,000 plus $90,100 divided by the 50¢ rate.

That means a moderately large ISO exercise stacked on a normal tech salary can trigger AMT in 2026 where the same exercise would have stayed under the line in 2025.

If you are planning an exercise-and-hold, model it before December 31, because splitting the exercise across two calendar years is the main lever for staying under the AMT crossover.

Long-term capital gains & NIIT (2026)

Shares held more than a year after vesting (RSUs) or after exercise (options) get these preferential rates on the appreciation.

8% Net Investment Income Tax stacks on top once your modified AGI crosses the threshold — and those NIIT thresholds are fixed by statute, never inflation-adjusted.

Payroll taxes & supplemental withholding (2026)

RSU vests and cash bonuses are "supplemental wages." Employers withhold a flat 22% federal on the first $1,000,000 of supplemental wages in the year, and 37% on anything above that.

If your marginal rate is 32% or 35%, the 22% withholding leaves a shortfall you must cover via a W-4 line 4(c) top-up or a quarterly estimate.

Retirement contribution limits (2026)

The §415(c) overall cap ($72,000) minus your elective deferral, employer match, and any profit-sharing is your Mega-Backdoor Roth room if your plan allows after-tax contributions plus in-service conversion.

High earners over the Roth IRA phaseout use the Backdoor Roth (non-deductible Traditional IRA → convert) for the $7,500.

Estimated tax & underpayment penalty (2026)

The IRS underpayment rate (federal short-term rate + 3 points, set quarterly under IRC §6621) stepped down from 8% in 2025 to 7% then 6% in 2026.

Withholding is treated as paid evenly across the year, so a December W-4 line 4(c) top-up can retroactively cure an earlier shortfall and defeat the penalty — a quarterly estimate only counts from the date you pay it.

Which calculator runs each of these?

Every Mathstub calculator runs in your browser with no signup — inputs never leave your device — and defaults to the 2026 tax year using exactly the figures on this page.

Bookmark this reference and re-check it each January, because most of these numbers move with inflation (and occasionally with legislation like OBBBA).