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RSU taxes for software engineers

Engineers often stack salary, bonus, and multiple RSU vests. plan withholding before each vest hits.

You are a software engineer at a public tech company with initial grant plus refreshers vesting on a predictable schedule. You want to know why flat withholding on each vest can still leave a tax bill when vests stack in one year.

Start here

Engineering comp at larger companies often combines salary, bonus, and overlapping grants. Each is wage income, usually withheld at a flat supplemental rate that may be below your when multiple vests land in the same tax year.

What you need before using this

  • Equity portal export of all active grants and dates this year.
  • Rough share price for upcoming vests.
  • Last pay stub showing year-to-date wages.
  • Filing status and state of residence.

Written for typical U.S. W-2 engineers at public companies. Your plan administrator's rules and state residency control the details.

Why this happens

Initial grants and refreshers create multiple streams that overlap.

Each is taxed as wages when it vests, not when the grant was signed.

Flat supplemental on each does not know about your other vests or spouse's income.

Job changes and remote moves can split wages across states in the same year.

What to check

  • Total expected income for the calendar year across all grants.
  • Whether combined salary plus pushes you into a higher bracket.
  • rate on each vs. your .
  • State reporting if you changed jobs or work locations.
  • Concentration risk if you hold vested shares instead of selling.

Evaluating each vest in isolation

A single $15,000 might look fine with flat . Four vests plus a bonus in the same year can land in a higher bracket where each flat-withheld underpaid. The gap shows up once, at filing, even though every individual notice looked reasonable.

What to check in your documents

  • Grant letters and refresh grant dates in the equity portal.
  • Quarterly confirmations and breakdowns.
  • after year-end: total wages vs. salary alone.
  • if you sold vested shares (basis often $0 without adjustment).
  • Offer letter or comp statement showing cadence (for planning, not tax proof).

Example scenario (hypothetical)

Illustration only, not your tax situation.

An engineer has an initial four-year grant and two refreshers, producing four vests totaling about $120,000 in one year. Each uses flat supplemental , but combined income sits in a higher bracket. The engineer uses a -gap estimate mid-year and increases W-4 on salary before the largest .

Questions people ask

Do refresh grants change how RSUs are taxed?
No special tax category. Each refresh vests and is taxed as wages on its own dates. The impact is volume: more grants mean more events in a year.
Should engineers sell immediately at vest?
Tax at is generally the same whether you sell or hold; holding adds market risk. Many engineers sell some shares to cover tax and reduce concentration in employer stock.
What changes if I join at a startup instead of FAANG?
Public mechanics ( as wages, , on sale) still apply once shares . Pre-IPO illiquidity and different grant types add other issues this page does not cover.
I'm on an H-1B — anything different?
Residency for tax purposes follows IRS rules, not visa type alone. Wage treatment at is similar for most employees, but international filings add complexity beyond this guide.

When to get help from a tax pro

  • You have several overlapping grants in one year.
  • You changed employers and have multi-state wages.
  • You hold a large concentrated position in company stock.
  • You want a repeatable plan across all vests.

Related calculators

Related pages

Sources and notes

Flat supplemental withholding on multiple vests vs marginal tax when income stacks in one year.

For learning, not filing

Grants, employers, and states all differ. Use your own documents and a qualified tax professional before you make decisions from this guide.