RSU vs Salary Tax Implications: Why Your Stock Compensation Hits Differently at Tax Time
Restricted Stock Units have become the default equity compensation vehicle at major tech companies, yet a surprising number of employees don't fully understand how they're taxed until they face an unexpected bill at year-end. A large RSU vest can push you into a higher marginal bracket, trigger the Additional Medicare Tax, and require quarterly estimated payments — all of which affect your real take-home pay far beyond what your base salary alone would suggest.
The Headline Tax Fact About RSUs
When your RSUs vest, the fair market value of those shares on the vest date is treated as ordinary income — exactly like wages. If 500 shares vest when the stock price is $60, you've just received $30,000 of taxable compensation. Your employer will withhold taxes and typically sell a portion of your shares to cover the bill (known as "sell-to-cover"). Use our salary calculator to model your total comp including RSU income.
RSU Taxation: The Full Timeline
At Grant
No tax event. You've been promised shares in the future, but you don't own them yet and owe nothing.
At Vesting
This is the taxable event. The FMV of shares on the vest date is included in your W-2 as ordinary income. You'll owe:
- Federal income tax at your marginal rate (22%, 24%, 32%, 35%, or 37%)
- Social Security tax (6.2%) if you haven't yet hit the $168,600 wage base
- Medicare tax (1.45% + 0.9% Additional Medicare Tax if total wages exceed $200,000)
- State income tax at your state's rate
The standard withholding rate for supplemental wages (which RSUs are classified as) is a flat 22% federal. But if your marginal rate is 32% or 35%, that 22% withholding creates an underpayment — and a surprise tax bill in April.
After Vesting: Capital Gains Phase
Once shares vest, your cost basis is the FMV at vest. From that point, any gains or losses are capital gains:
- Held under 12 months: Short-term capital gains taxed as ordinary income
- Held 12+ months: Long-term capital gains taxed at 0%, 15%, or 20% depending on your income
RSU vs. Base Salary: A Tax Comparison
| Income Type | $100K Base | $30K RSU Vest | Combined |
|---|---|---|---|
| Gross Income | $100,000 | $30,000 | $130,000 |
| Effective Federal Rate | ~17.2% | ~24% (marginal) | ~18.8% |
| Federal Tax | ~$17,200 | ~$7,200 | ~$24,400 |
| FICA | $7,650 | $2,295 | $9,945 |
| CA State Tax (est.) | ~$6,500 | ~$2,700 | ~$9,200 |
| Net Value | ~$68,650 | ~$17,805 | ~$86,455 |
The Underpayment Problem and How to Fix It
Because RSUs are withheld at the flat 22% supplemental rate but your marginal rate may be higher, many tech employees end up owing substantial amounts at tax filing. Solutions:
- Increase W-4 withholding — Submit a new W-4 requesting additional withholding each paycheck to pre-pay the expected RSU tax deficit
- Make quarterly estimated payments — If your total underpayment will exceed $1,000, pay estimates by January 15, April 15, June 15, and September 15
- Request higher withholding at vest — Some employers and brokerages allow you to request a withholding rate above 22% at vest events
83(b) Elections: For Restricted Stock Only (Not RSUs)
The 83(b) election allows founders and early employees receiving restricted stock (not RSUs) to pay tax on the grant date value rather than the vesting date value. This strategy is not available for standard RSUs but is critical knowledge for startup founders receiving cheap shares early.
State Tax Considerations for RSU Vesting
If you live and work in different states during a vesting period, you may owe taxes in multiple states. California is particularly aggressive about sourcing RSU income to the state — if you worked in California during any part of the vesting period, California will assert the right to tax a pro-rata share of those RSUs even if you've since moved to a no-tax state. Compare your after-RSU net pay across states to understand the full picture.
Strategies to Reduce RSU Tax Burden
- Max out 401(k) — Every dollar contributed pre-tax reduces the income base on which RSU income stacks
- Harvest capital losses — Offset capital gains from sold RSU shares with losses elsewhere in your portfolio
- Donate appreciated shares — Give vested RSU shares directly to charity to avoid capital gains and claim a full FMV deduction
- Time large vests strategically — If you have control over grant timing, vesting in a lower-income year reduces marginal rates
The Bottom Line
RSUs are real compensation — often representing 20–50% of total annual pay at major tech companies. Treating them as "bonus money" you can ignore until tax season is a costly mistake. Model your RSU income alongside your base salary using our take-home pay calculator to set accurate withholding and avoid year-end surprises.