RSU Taxation at Vest Explained

When a restricted stock unit (RSU) vests, you owe ordinary income tax on the fair market value of the shares as if you had received cash wages — and that value becomes your cost basis for calculating capital gains or losses when you later sell.

The vest date is the taxable event

The critical moment for RSU taxation is the day shares vest—when restrictions on the shares lift and you gain full ownership. On that date, the IRS treats the fair market value of the vested shares as ordinary wage income, regardless of whether you hold or sell them. Your employer reports this on Form W-2 as if you had received a cash bonus. If your company grants you 100 RSUs worth $50 each and they vest in full on a single day, you owe ordinary income tax on $5,000 that year, at your marginal tax bracket.

This differs fundamentally from stock options, where the taxable event (for incentive options) typically occurs at exercise or sale, not at grant. RSU taxation is immediate and mandatory at vest, which is why RSU holders often see an unexpected spike in annual tax liability.

Ordinary income, not capital gains

The income from vesting is taxed as ordinary income—the same rate as salary and bonus. It does not receive the preferential treatment of long-term capital gains. If your marginal rate is 35%, you owe roughly $1,750 on that $5,000 vest event. This is why many employees receive fewer shares than the nominal RSU grant: the company withholds shares (an auto-sell) to cover the tax bill.

Suppose you are granted 100 RSUs at $50 per share. On vest day, your company withholds 35–40 shares to pay your income tax and sends you the remaining 60–65 shares plus a Form W-2 reporting $5,000 of compensation. You’ve effectively paid your tax obligation by giving up shares rather than cash from your bank account.

Cost basis is locked at the vest date

Once ordinary income tax is paid at vest, the fair market value on the vest date becomes your cost basis for future capital gains or losses. This is crucial for planning a later sale.

Example: Your 100 RSUs vest on 15 January at $50 per share. After withholding, you own 65 shares (having surrendered 35 to tax), and your cost basis is $50 per share on the 65 shares you received. If you sell those 65 shares on 20 March at $70 per share, you realize a capital gain of $20 per share × 65 = $1,300. That gain will be taxed as a long-term or short-term capital gain depending on whether you held the shares more than a year from the vest date, not from the grant date.

This holding period distinction matters. Many employees assume that a multi-year RSU vesting schedule (common: four years, vesting quarterly) means they automatically qualify for long-term capital gains treatment. It does not. The holding period restarts on each vest date. A vest on 15 January followed by a sale on 10 January the next year triggers short-term capital gains tax on the appreciation, because you held those particular shares for less than one year.

The grant date does not start the holding period

A common confusion: employees hold RSU grants for years (from grant through vesting), yet the tax-holding clock starts at vest, not at grant. From the IRS’s perspective, you don’t own the shares until restrictions lapse; the grant period is simply compensation deferred. To receive long-term capital gains rates, you must hold the vested shares (the actual shares delivered at vest) for at least one additional year after the vest date.

If you want to minimize short-term tax on a fast-growing RSU position, you must either hold for a full year post-vest or accept short-term rates if you need to sell sooner—perhaps to rebalance, to meet a major expense, or to reduce concentration risk in company shares.

Employer withholding: shares or cash

Most large employers offer RSU participants a choice: withhold shares to cover the tax bill, or withhold cash. In practice, withholding shares is the default and most straightforward. Your employer sells a portion of the vested shares at fair market value and uses the proceeds to pay your federal, state, and payroll taxes, delivering you the net remainder. This avoids the need for you to scramble for cash on a vest date.

If you elect cash withholding, you must provide the funds to your employer by the vest date. This is rare outside closely held companies. Most employees don’t want to write a check to their employer when RSUs vest; the automatic share withholding saves that friction. It also means you pay taxes in a tax-deferred account if your RSUs vest in a 401(k) brokerage window, though few RSU plans permit this (most are held in a broker account).

No deduction for RSU vesting

Unlike mortgage interest or certain capital losses, you cannot deduct the ordinary income from RSU vesting. The tax is paid once, on vest day, at your ordinary rate, and that is final. However, if the stock later declines in value before you sell, you can claim a capital loss to offset other gains.

Example: RSUs vest at $50, you hold until the stock drops to $35 and sell. Your cost basis remains $50; you have a $15 loss per share. You can use this loss to offset other capital gains that year, or carry it forward to future years, subject to tax-loss harvesting rules.

Double taxation risk with forfeiture

Some complex RSU arrangements include provisions for forfeiture upon termination or failure to meet performance targets. If an RSU is forfeited after vesting but before sale, the tax rules can create harsh outcomes. You owe ordinary income tax on the vest date (even if the RSU is later forfeited), but no refund is granted if you never actually receive the shares. This is why it’s essential to read your RSU agreement carefully and understand any contingencies.

A small subset of RSUs—those granted under Section 83(b) elections—allow you to elect early inclusion of ordinary income at grant date rather than vest date. This is rare and typically used only in startups where the stock value at grant is near zero and you expect rapid appreciation. For ordinary RSUs, there is no Section 83(b) election to defer or accelerate taxation; vest date is mandatory.

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