Equity Compensation Tax Planning: RSUs, ISOs, and NQSOs

The three main forms of equity compensation

Most equity comp falls into one of three structures. The tax treatment differs significantly, and confusing them is expensive.

RSUs: Where the withholding gap lives

Restricted stock units are the most common form of equity comp today. When shares vest, the entire fair market value on the vest date becomes ordinary income — reported on your W-2 — and is subject to all applicable payroll taxes.

How RSUs are taxed at vest

• Ordinary income tax: FMV of vested shares × number of shares = W-2 income. At $2M–$20M total income, your marginal rate is almost certainly 35% or 37% — but your employer withholds at the IRS supplemental wage rate of 22% (or 37% only if cumulative supplemental wages exceed $1 million in a calendar year).¹
• Social Security: 6.2% on wages up to $184,500 in 2026 (combined across all wages, including RSU income — if you've already hit the cap from salary, no additional SS tax is owed on the vest).²
• Medicare: 1.45% on all wages, plus the 0.9% Additional Medicare Tax on wages above $200,000 (single) or $250,000 (MFJ) combined for the year.¹

The sell-to-cover question

Most equity plans offer three settlement options at vest: sell-to-cover (sell enough shares to cover withholding), same-day sale (sell all), or hold (keep all shares, fund the tax separately). The choice is often presented as an administrative default — but it's actually a financial planning decision with real consequences:

• Same-day sale: Immediate liquidity, no concentration risk, but no upside capture if the stock rises. Tax bill due in April is still real, just smaller.
• Sell-to-cover + hold remainder: Keeps some upside but creates concentration risk. Your effective withholding is 22%, not your true marginal rate — expect a tax bill unless you separately fund the gap.
• Hold all shares: Maximum upside potential, maximum concentration risk, maximum cash out-of-pocket at tax time. Only makes sense if you can fund the full tax separately and are intentionally building an investment position in employer stock.

At $2M+ net worth, most fee-only advisors recommend treating RSUs as automatic diversification events: sell as they vest, unless you have a specific thesis for concentrated ownership. See our concentrated stock guide for the math on holding vs. diversifying a large employer position.

If you hold after vest: the basis and holding period

When you hold shares past vest, your tax basis is the FMV on the vest date — the income you already reported. Appreciation from there forward is capital gain. Hold longer than 12 months from vest, and it's long-term capital gain taxed at 20%+3.8% NIIT for high earners. Hold less than 12 months, and it's short-term — taxed as ordinary income at up to 37%.

This creates an important decision point for shares vested late in the year: if you're close to the 12-month mark, waiting to sell until after the anniversary converts a potentially 37% gain into a 23.8% gain. On $200,000 of appreciation, that's a $26,400 difference.

ISOs: The AMT trap high earners hit without expecting it

Incentive stock options are more tax-favorable than NQSOs on paper — no regular income tax at exercise. In practice, high earners face a significant AMT exposure that can eliminate most of that advantage, and the interaction with the $100K annual limit creates planning constraints.

How ISOs are taxed

When you exercise ISOs, you pay nothing in regular income tax. The spread (FMV at exercise minus exercise price) is, however, an AMT preference item — it gets added back to income for AMT purposes. If your AMT liability exceeds your regular tax liability, you pay the difference.

The 2026 AMT structure after OBBBA:³

• AMT exemption: $140,200 (MFJ, 2026). This amount is subtracted from your AMT income before the rate applies.
• AMT phaseout: The exemption phases out at $0.25 per dollar of AMTI above $1,000,000 (MFJ). At $1.56M AMTI, the exemption is fully phased out.
• AMT rates: 26% on the first $232,600 of AMTI above the exemption; 28% on amounts above $232,600.

The $100K annual ISO limit

Under IRC §422(d), only $100,000 of ISOs can become exercisable in any calendar year at favorable rates (measured by FMV at grant). Options exceeding this limit are automatically treated as NQSOs. This limit constrains how fast you can exercise beneficially — especially when options have appreciated significantly.

Qualifying vs. disqualifying dispositions

To get the long-term capital gain treatment on the full gain (exercise price to sale price), you must hold:

• More than 2 years from the grant date, AND
• More than 1 year from the exercise date

If you sell before meeting both tests, you have a "disqualifying disposition" — the spread at exercise becomes ordinary income, essentially converting the ISO to NQSO economics retroactively. The gain above the exercise-date FMV remains capital gain.

QSBS and startup ISOs

If your ISOs are in a qualifying startup that meets Section 1202 requirements, the OBBBA (July 2025) raised the QSBS exclusion to $15 million per taxpayer, per investment. Tiered holding periods apply: 50% exclusion at 3 years, 75% at 4 years, 100% at 5+ years.⁴ If your ISO gain qualifies as QSBS, the interaction between ISO exercise timing, AMT, and QSBS holding periods deserves careful modeling — the right order of operations can eliminate millions in tax.

NQSOs: Simpler, but still requires timing judgment

Non-qualified stock options trigger ordinary income tax at exercise, on the spread between FMV and exercise price. That income is reported on your W-2 and is subject to FICA taxes — both SS (up to the $184,500 wage base) and Medicare (including the 0.9% additional above applicable thresholds).

Your basis in the shares becomes the FMV at exercise. Any subsequent appreciation (if you hold) is capital gain — long-term if held 12+ months, short-term otherwise.

The one planning lever: exercise timing

Unlike RSUs (which vest on a schedule you largely don't control), NQSOs can often be exercised at any time during their term. This creates a meaningful planning opportunity:

• Exercise in a low-income year: The year you retire, take parental leave, or have minimal bonus — moving the exercise to a lower marginal rate can save 12–15 percentage points on a large spread.
• Exercise across multiple years: If you have $2M in exercisable NQSOs, exercising $400K/year for 5 years can keep you out of the top bracket each year, vs. a single exercise that puts all $2M at 37%.
• Watch the bracket ceiling: In 2026, the 35%–37% threshold for MFJ is $768,700 of taxable income. If your salary + bonus puts you at $600K, exercising more than ~$168K of additional NQSO spread in that year tips the full additional amount into 37%. Model the ceiling before exercising.

83(b) elections for restricted stock awards

If you receive actual restricted stock (not RSUs, which have no underlying shares until vest), you can file an IRC §83(b) election within 30 days of grant. This makes the FMV at grant date your W-2 income immediately — paying ordinary income tax upfront when the value is low — and starts the long-term capital gain holding period from the grant date.

The 83(b) election makes sense when: (1) the stock is at a low value and you expect significant appreciation, and (2) you have the cash to pay the upfront tax. It's particularly common in early-stage startups where shares may be nearly worthless at grant but valuable if the company succeeds. Missing the 30-day window is irreversible — this is one of the most time-sensitive decisions in equity comp planning.

Interactive RSU Tax Estimator

This calculator estimates the federal income and FICA tax on an RSU vesting event, the withholding gap vs. your employer's default 22% supplemental withholding, and after-tax proceeds if you sell immediately vs. hold to the long-term threshold. All calculations use 2026 MFJ brackets and rates.⁵

Coordinating equity comp with your broader financial plan

Roth conversions and vesting years

RSU vesting events push income high in the year they occur — often into 35% or 37% brackets. This is typically the worst time to do a Roth conversion, which stacks on top of the vest income. The better pattern: use the years between large vesting events (or after your last grant vests) to do Roth conversions at lower rates. See our Roth conversion guide for the bracket-filling approach.

IRMAA awareness for near-retirement executives

If you're within 2 years of Medicare eligibility (age 65), be aware that IRMAA is based on income from 2 years prior. A large RSU vest or NQSO exercise at age 63 shows up in your Medicare premiums at 65. The 2026 IRMAA Tier 1 threshold is $218,000 MAGI (MFJ). A vest that pushes you to $500K MAGI can add $2,440+/year per person in Medicare premiums. See our IRMAA planning guide.

Asset location after the vest

Shares you hold post-vest in a taxable account are already taxable assets. The planning question becomes where to hold other investments: bonds and REITs, which generate ordinary income, belong in tax-deferred or Roth accounts; the employer stock you're holding for LTCG treatment naturally stays in taxable. See our asset location guide for the full account-type analysis.

The concentrated position problem

A decade of RSU vesting in a single employer can leave you with a $2M–$5M concentrated position — even after systematic sell-to-cover. By the time you notice, the unrealized gain is large enough that a full sale costs $400K–$600K in federal taxes alone. The concentrated stock guide covers phased sales, DAF donations, exchange funds, and collars — the practical toolkit for unwinding without the full tax hit.