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RSU taxes when equity is a big share of your pay

When RSUs are a large share of pay, withholding gaps and surtaxes deserve a deliberate plan.

Rates and rules change. Content is reviewed for tax year 2026. Check the last-reviewed date and methodology on each page, then confirm against IRS or state guidance before you file.

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In plain terms

When are a large part of your compensation, two things deserve a plan: the gap from flat rates, and surtaxes that can apply at higher income. Both are manageable if you estimate them before the bill arrives, not after.

How the tax works

Flat can be well below your , creating a large gap in dollar terms.

Additional Medicare tax and net investment income tax can apply at higher income levels.

Multiple vests and other income compound the gap across the year.

Closing the gap is easier with extra or estimated payments than with a single April payment.

What to check on your end

  • Your full-year income including all vests and household income.
  • The flat rate vs. your .
  • Whether surtaxes apply to you this year.
  • Whether estimated payments or extra is the cleaner fix.
  • Your concentration in company stock.

Common mistake

Treating each as covered because tax was withheld. At higher incomes, flat routinely trails the real rate, and surtaxes add to the gap.

Example scenario (hypothetical)

Illustration only, not your tax situation.

Example: a high earner expects $300,000 of vests withheld at a flat rate. The plus surtaxes is higher, so they estimate the shortfall mid-year and raise or pay estimates to avoid a large April bill.

When a CPA is worth it

  • Equity is a large share of your pay.
  • Surtaxes likely apply to you.
  • You want a repeatable estimated-payment routine.
  • You are deciding when to diversify concentrated stock.

Sources and notes

Primary tax claims on this page are supported by the official and secondary sources below. Broker and software links describe reporting mechanics — confirm rules against IRS or state guidance.

Employee equity tax planning context — not role-specific tax law.

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For learning, not filing

VestingTax.com is not a CPA firm or tax preparer. Grants, employers, and states all differ. Use the cited IRS and state sources above, your own documents, and a qualified tax professional before you make decisions from this guide.

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