If your compensation package includes Restricted Stock Units (RSU), understanding how they’re taxed isn’t optional — it directly affects your take-home pay, your tax bill, and how much you might owe (or overpay) at filing time. Here’s exactly how RSU taxation works, at vesting and at sale.
What Are RSUs, Quickly
Restricted Stock Units are a promise from your employer to give you company stock once certain conditions are met — typically a vesting schedule based on time (e.g., 25% per year over four years). Unlike stock options, RSUs have real value the moment they vest, regardless of the stock price, which is exactly why they’re taxed differently than options.
Taxation at Vesting: The Moment That Matters Most
RSUs are taxed as ordinary income at the moment they vest — not when you’re granted them, and not when you eventually sell them.
Here’s what happens:
- When a batch of RSUs vests, the fair market value of those shares on that date is added to your W-2 income for the year.
- This amount is subject to federal income tax, Social Security tax (up to the annual wage base), Medicare tax, and any applicable state income tax — exactly like a cash bonus would be.
- Your employer is required to withhold taxes on this income, typically by automatically selling a portion of the vested shares (called “sell-to-cover”) to satisfy the withholding requirement.
Example: If 100 shares vest at $150/share, that’s $15,000 in ordinary income added to your W-2 for the year, taxed at your marginal rate just like salary.
The Default Withholding Rate Is Often Too Low
This is the single most common — and most expensive — mistake among RSU recipients.
Most employers default to withholding RSU income at the flat supplemental wage rate (22% federally for amounts up to $1 million in supplemental wages in a calendar year, higher above that threshold). If your actual marginal tax bracket is higher than 22% — which is common for many tech employees once RSU income is added to base salary — you’ll owe additional tax when you file, sometimes a significant and unexpected amount.
What to do about it:
- Estimate your total income including RSU vests for the year and compare it to your actual marginal bracket
- If there’s a gap, consider making quarterly estimated tax payments or requesting additional withholding from your regular paycheck to cover the shortfall
- Don’t assume the automatic sell-to-cover shares withheld enough — check the math yourself, especially in years with large vesting events
Taxation at Sale: Capital Gains, Not Income Tax
Once RSUs vest and become your shares, any further gain or loss when you eventually sell is treated separately — as a capital gain or loss, not ordinary income.
Your cost basis for this calculation is the fair market value on the vesting date (the same amount already taxed as ordinary income) — not zero, and not the original grant price.
Two scenarios:
- Sell immediately at vesting: Little to no capital gain or loss, since the sale price is essentially the same as the vesting-date value already taxed. This is why many financial advisors recommend selling RSUs promptly rather than holding.
- Hold and sell later: Any increase above the vesting-date value is a capital gain; any decrease is a capital loss. Whether it’s taxed at short-term (ordinary income rates) or long-term (lower capital gains rates) depends on how long you held the shares after vesting — not from the original grant date.
Short-Term vs. Long-Term Capital Gains on RSUs
| Holding period after vesting | Tax treatment |
|---|---|
| Less than 1 year | Short-term capital gains (taxed as ordinary income) |
| 1 year or more | Long-term capital gains (typically 0%, 15%, or 20% depending on income) |
Holding shares for over a year after vesting can meaningfully reduce the tax rate on any additional appreciation — but this needs to be weighed against concentration risk, discussed below.
The Overlooked Risk: Concentration in a Single Stock
Many tech employees end up with a large percentage of their net worth tied up in their employer’s stock simply because RSUs keep vesting and few people actively sell and diversify. This creates real risk: your income and a large portion of your investments depend on the same company’s performance.
A common approach many financial planners recommend: sell RSUs as they vest (or shortly after) and reinvest the proceeds into a diversified portfolio, rather than holding concentrated employer stock indefinitely — treating RSU income more like a cash bonus that happens to arrive as stock.
RSUs vs. Stock Options: Why the Tax Treatment Differs
Stock options are only taxed when you actually exercise them (and again when you sell), and the tax treatment can vary significantly depending on whether they’re incentive stock options (ISOs) or non-qualified stock options (NSOs). RSUs are simpler by comparison — there’s no exercise decision, no strike price, and the ordinary income tax hits automatically and immediately at vesting, whether you want it to or not.
Frequently Asked Questions
Do I owe taxes on RSUs I haven’t sold yet? Yes — the ordinary income tax hits at vesting regardless of whether you sell the shares. Many people are surprised to learn they owe tax on stock they still hold.
What if my company’s stock price drops after vesting but before I sell? You’ve still paid ordinary income tax on the value at vesting. If you later sell at a lower price, you can typically claim a capital loss for the difference, which can offset other capital gains or a limited amount of ordinary income.
Can I avoid the ordinary income tax on RSUs entirely? No — this is simply how RSUs are taxed by design; there’s no legal way to convert RSU vesting income into capital gains treatment. The only real tax planning lever is managing withholding accuracy and choosing when to sell after vesting.
Should I always sell RSUs immediately when they vest? Not always, but it’s a common and reasonable default for managing concentration risk and simplifying tax planning — the right choice depends on your overall portfolio, tax situation, and confidence in the company’s future performance.
This article is for informational purposes only and does not constitute tax or financial advice. Tax rates, withholding rules, and thresholds change and vary by individual circumstance — consult a licensed CPA or tax professional for guidance specific to your equity compensation.