RSU Tax Planning: How Vesting and Taxes Actually Work

Restricted stock units (RSUs) are one of the most common ways employees at public and pre-IPO companies build wealth — and one of the most misunderstood at tax time. The mechanics are not complicated, but the cash-flow and concentration consequences catch a lot of people off guard.

This guide explains how RSUs vest, how they're taxed at each stage, where the common withholding shortfall comes from, and how to think about the concentrated position they leave you holding. It is educational only and not tax or investment advice — your own situation, state, and the specifics of your grant matter, so confirm details with a qualified tax professional.

What an RSU actually is

An RSU is a promise from your employer to give you shares of company stock once certain conditions — almost always continued employment over a vesting schedule — are met. Until the units vest, you own nothing you can sell; you hold a contractual right, not stock.

A typical grant vests over several years, often with a one-year cliff followed by periodic vesting (monthly, quarterly, or annually). Some grants, especially at pre-IPO companies, add a second condition such as a liquidity event before the shares are truly yours.

How RSUs are taxed at vesting

The key fact: RSUs are taxed as ordinary income when they vest, not when they're granted and not when you eventually sell. On each vest date, the fair market value of the newly vested shares is treated as compensation — it shows up on your W-2 just like salary.

Because it's ordinary compensation income, it's subject to federal income tax, Social Security and Medicare, and any applicable state income tax. The amount is the share price on the vest date multiplied by the number of shares vesting. From that moment, those shares have a cost basis equal to that same fair market value.

The withholding gap that surprises people

Employers usually withhold taxes on vesting by selling or holding back a portion of the vested shares (often called 'sell to cover'). The problem is that the default supplemental-wage withholding rate may be lower than your actual marginal tax rate, especially if RSUs push a meaningful amount of income into a higher bracket.

When too little is withheld, the shortfall becomes due when you file — sometimes a large, unexpected bill. People with significant RSU income often need to make estimated tax payments or adjust withholding elsewhere to avoid a surprise and potential underpayment penalties.

Selling vested shares: capital gains

Once shares have vested, any further change in value is a capital gain or loss, measured from the vest-date basis. Sell soon after vesting and the gain is usually small (the income was already taxed at vest). Hold longer and you take on market risk in exchange for potential long-term capital-gains treatment after the required holding period.

A common and clean approach is to consider selling at or near vest, since the shares are taxed as income either way and selling immediately removes incremental concentration risk. Whether that's right for you depends on your conviction, your tax picture, and how concentrated you already are.

Concentration is the quieter risk

Steady vesting can leave you holding a large, growing position in a single company — often the same company that pays your salary. That doubles your exposure: a downturn can hit your portfolio and your job at the same time.

Deciding how much company stock to keep is a portfolio and risk question, not just a tax one. Many people set a rule for themselves — a target maximum percentage of net worth in any single name, or a schedule for trimming on each vest — so the decision is made calmly in advance rather than emotionally in the moment.

Know your true marginal rate so you can cover the withholding gap before filing.
Track each lot's vest-date basis to compute gains correctly when you sell.
Decide a concentration limit in advance and revisit it on every vest.
Coordinate large sells with the rest of your tax year (other income, deductions, charitable giving).

Frequently asked questions

When are RSUs taxed — at grant, vest, or sale?

RSUs are taxed as ordinary income at vesting, based on the share price on the vest date. After vesting, any additional gain or loss when you sell is a capital gain or loss measured from that vest-date value.

Why do I owe more tax than my employer withheld on my RSUs?

Employers often withhold at the default supplemental-wage rate, which can be lower than your actual marginal tax rate. If RSU income pushes you into a higher bracket, the difference becomes due at filing — which is why many people make estimated payments or adjust withholding.

Should I sell my RSUs as soon as they vest?

There's no universal answer. Because the shares are taxed as income at vest regardless, selling at vest is a clean way to reduce single-stock concentration. Holding takes on market risk for potential long-term capital-gains treatment. The right choice depends on your concentration, conviction, and tax situation.

How Velira helps with RSUs

Velira treats vested company stock as what it is — a real, often concentrated position on your balance sheet — and keeps it visible against your whole picture rather than buried in a brokerage tab. Unvested grants and any liquidity-contingent shares are held as contingent, not blended into your confirmed net worth, so you always see the honest floor separately from the upside.

Grounded in survival math, Velira flags when a single position has grown past a sensible share of your net worth and tells you the move your plan calls for — trim, hold, or protect — with a rule trace you can inspect. It is read-only and never executes; you place every order yourself. Velira is decision-support, not tax or investment advice.