Quick Answer: How Are RSUs Taxed?
Restricted Stock Units are taxed in two distinct phases: Phase 1 (Vesting), where the fair market value of all vested shares is taxed as ordinary W-2 income (federal, state, FICA); and Phase 2 (Sale), where only the gain above the vesting cost basis is taxed as capital gains(short-term if held ≤1 year, long-term 15%–20% if held >1 year).
The RSU Tax Lifecycle Explained
Understanding the three milestone events in an RSU schedule prevents costly tax penalties and liquidation surprises:
Your employer grants you a promise of stock over a vesting schedule (e.g. 4-year vest with 1-year cliff). No tax liability occurs on grant date.
Shares officially become yours. FMV is taxed as Ordinary Income. Brokerage executes Sell-to-Cover to pay mandatory withholding. Cost basis is established.
When you sell retained shares, you only owe Capital Gains Tax on the profit above your cost basis (Sale Price - Vest Price).
RSU Tax Formula Reference
Step-by-Step Case Study: The 22% Withholding Trap
Consider Marcus, a senior software architect earning $220,000 base salary whose company vests 500 RSU shares at $120/share ($60,000 gross vest value):
- Default Brokerage Withholding:
The brokerage withholds the mandatory 22% federal rate ($13,200), selling 110 shares to cover the tax and depositing the remaining 390 shares into Marcus's account. - Actual Tax Liability at Filing:
Because Marcus's combined income puts him in the 35% federal marginal tax bracket, his true federal tax liability on the $60k vest is 35% × $60,000 = $21,000. - The Resulting Tax Gap:
Marcus has an under-withheld shortfall of $21,000 - $13,200 = $7,800 due at tax time. If unplanned, this creates sudden cash crunches or IRS estimated tax penalties.
Comparison: RSUs vs ISOs vs NSOs vs ESPP
| Equity Type | Tax at Vesting | Tax at Exercise | Downside Risk |
|---|---|---|---|
| RSUs (Restricted Stock) | Ordinary Income on FMV | N/A (No exercise needed) | Always holds monetary value (unless stock goes to $0) |
| Incentive Stock Options (ISOs) | No tax at vest | AMT (Alternative Minimum Tax) spread | Options can expire worthless ("underwater") |
| Non-Qualified Options (NSOs) | No tax at vest | Ordinary income on spread | Options can expire worthless |
| ESPP (Employee Stock Purchase) | N/A | Discount taxed upon purchase/sale | Capital risk if held past purchase |
Pro Strategies to Optimize RSU Taxes
- Increase Brokerage Withholding Election: Many modern plan administrators (Shareworks, Fidelity, Morgan Stanley) allow you to elect voluntary withholding at 37% rather than 22% to eliminate year-end tax surprises.
- Max Out Pre-Tax Accounts: Maximize contributions to traditional 401(k) ($23,000) and Health Savings Accounts (HSA) to depress your Adjusted Gross Income during high-vest years.
- Tax-Loss Harvesting: Offset capital gains from RSU sales by realizing losses in other underperforming brokerage investments.
- Charitable Gifting of Long-Term Stock: Donate appreciated RSU shares held >1 year directly to Donor-Advised Funds (DAFs) to avoid 100% of capital gains taxes while taking full market value deductions.