RSU Vest and Sell vs Hold: Tax Decision Math

A 1,000-share restricted stock unit (RSU) vest at $85 per share generates $85,000 in ordinary income. For a California resident in the top federal bracket, the combined tax bill on that single event runs roughly $43,988 — leaving $41,012 in hand before the shares have moved a dollar. That is a Finluxy Equity After-Tax Yield of 48.3%. The number most equity-comp coverage skips is what happens after vest, when the decision to sell immediately or hold becomes a second, separate tax bet layered on top of the first.

The vest-and-sell versus hold question is usually framed as a conviction call on the stock. It is also a tax-structure call, and the two are not the same. Selling at vest converts paper value into cash at a known cost. Holding starts a capital gains clock that can cut the rate on future appreciation nearly in half — or expose you to a loss on shares you have already paid full ordinary-income tax to receive.

The numbers that define the decision

Five figures frame every vest-and-sell-versus-hold choice for a high earner. They are the rates and thresholds that determine how much of an RSU you keep at vest and how much a later sale costs.

Sources: IRS Revenue Procedure 2025-32 (October 2025); IRS Topic 559/Form 8960 NIIT guidance (2026); California Franchise Tax Board 2026 tax schedules. Behavioral Health Services Act surcharge applies above $1M taxable income.

The ordinary rate at vest and the capital gains rate on later appreciation are the two prices in this transaction. The gap between them — 37% versus 20% federally, before NIIT — is the entire economic argument for holding. Everything else is execution risk.

What you actually owe at vest

RSUs are taxed as ordinary income at vest: the fair market value (FMV) on the vest date multiplied by shares vested equals the income added to your W-2. There is no election, no timing flexibility, no holding period that changes this. The shares are taxed the moment they become yours.

Walk through the 1,000-share example at $85 FMV. The $85,000 of ordinary income stacks on top of a salary that, for a $150k+ household, has already filled the lower brackets. At the 37% federal marginal rate, that vest costs $31,450 in federal tax. California, which does not offer a preferential rate for this income, takes 13.3% at the top — $11,305. Medicare’s base 1.45% adds $1,233. Sum: $43,988 in tax on $85,000 of value.

Sources: IRS Revenue Procedure 2025-32 (2026 federal brackets); California Franchise Tax Board 2026 schedules; IRS Medicare tax guidance. Top-bracket assumption; the 0.9% Additional Medicare Tax above $200,000 would add $765, lowering yield further. Figures illustrative.

A note on the Medicare layer, because it is where most simplified models understate the bill. The base Medicare rate of 1.45% has no wage cap, so it applies to every dollar of vest income. Above $200,000 in wages, an Additional Medicare Tax of 0.9% applies — for a high earner whose salary already exceeds that threshold, the full vest income carries 2.35% Medicare, pushing the yield below the 48.3% shown. The single-event yield is a floor estimate; stacked on existing high wages, the real marginal cost is higher. This is the same dynamic detailed in the breakdown of net RSU yield after all taxes.

Sell at vest: the cleanest tax outcome

Selling on the vest date, or within a day or two of it, produces the most predictable result. Your cost basis is the FMV at vest — the same figure you were just taxed on. Sell at that price and there is no additional gain, no additional tax. The $41,012 net is what you keep.

This is the often-misunderstood mechanic worth stating plainly: vesting and selling at the same price is not “double taxation.” You pay ordinary income tax once, at vest. A same-day sale realizes essentially zero capital gain because basis equals sale price. The only friction is bid-ask spread and any intraday price movement between vest and execution. For a high earner who would otherwise hold a concentrated single-stock position, selling at vest and redeploying into a diversified portfolio is the tax-neutral default — you have already paid the expensive tax, and the cash comes out clean.

The case for selling strengthens when the RSU sits inside an employer concentration you would never build deliberately. A senior engineer with four years of vested grants can easily hold 40% of liquid net worth in one ticker. Selling at vest is the mechanism that breaks that concentration without triggering a fresh tax event, which is why it pairs naturally with the timing rules inside a 10b5-1 trading plan for insiders restricted by blackout windows.

Hold: a second tax bet on top of the first

Holding past vest changes the character of future gains. From the vest date forward, the shares behave like any purchased stock with a cost basis equal to the vest-date FMV. Sell within a year and any appreciation is a short-term capital gain — taxed at ordinary rates, the same 37% federal you already faced. Hold more than a year and the appreciation qualifies for long-term capital gains (LTCG) treatment: 0%, 15%, or 20% federally depending on total taxable income, with the 20% rate applying to a top-bracket filer.

That rate differential is the prize. On post-vest appreciation, a top-bracket filer pays 20% LTCG instead of 37% ordinary — a 17-percentage-point federal saving on every dollar of growth held long enough to qualify. The structural logic mirrors the appreciation-conversion argument behind an 83(b) election timing decision, though RSUs cannot use 83(b) the way early-exercised options can.

The saving is real but conditional. Three costs erode it. First, NIIT: for a high earner, post-vest appreciation is investment income, and the 3.8% Net Investment Income Tax applies on top of the 20% LTCG, lifting the effective federal rate on gains to 23.8%. Second, California offers no break — the state taxes capital gains as ordinary income, so the 13.3% top rate applies whether you sell at vest or five years later. Third, and largest, is the undiversified risk you carry for the holding period. You are wagering the spread between 37% and 23.8% against the possibility that a concentrated position falls.

Sources: IRS Revenue Procedure 2025-32; IRS Form 8960 NIIT guidance; California Franchise Tax Board 2026 schedules. Rates apply to appreciation above vest-date basis, not the vest income itself. California does not provide a preferential capital gains rate.

Read that table as the cost of impatience. Selling appreciated shares before the one-year mark costs a top-bracket Californian 54.1% of the gain versus 37.1% for waiting — a 17-point penalty for selling early, the same gap that exists at the federal level. The holding-period clock is worth real money only if the stock holds its value while it runs.

Putting a number on the hold decision

Assume the 1,000 shares vest at $85 and you hold. Two years later they trade at $110. You sell. The appreciation is $25 per share, $25,000 total, all long-term capital gains. At the combined 37.1% on the gain, you owe $9,275, netting $15,725 of the $25,000 appreciation on top of your original $41,012 net from vest.

Run the counterfactual. Had you sold the same $25,000 of growth as a short-term gain, the combined 54.1% would have cost $13,525 — netting only $11,475. Holding long enough to clear the one-year line saved $4,250 on a $25,000 gain. That is the entire quantifiable benefit of holding, and it materializes only if the stock is actually up when you sell.

Now the downside case, which most coverage omits. Suppose the shares fall to $60. You were taxed at vest on $85,000 of ordinary income — you paid $43,988 in tax on value you no longer hold. Selling at $60 realizes a $25,000 capital loss, which offsets other capital gains and, beyond that, only $3,000 of ordinary income per year. The tax you already paid at vest does not come back. You financed a full ordinary-income tax bill on phantom value. This asymmetry — full tax at vest, capped loss relief on the way down — is the strongest mechanical argument against reflexive holding.

The overlooked insight

Most RSU guidance frames hold-versus-sell as a 37%-versus-20% rate arbitrage and stops there. The dataset says the rate gap is the smaller story. The larger one is that the ordinary-income tax at vest is sunk and irreversible the instant the shares vest, while the capital gains advantage of holding is contingent on the stock not falling. You are not choosing between two rates. You are choosing between a certain, already-paid cost and a conditional future saving that a single bad quarter can erase.

Quantify the asymmetry. Holding the example shares a full year to clear the LTCG threshold saves $4,250 on $25,000 of appreciation if the stock rises 29%. But a 29% decline produces a $25,000 loss against which you have already paid $43,988 in vest tax — and the loss only shelters $3,000 of ordinary income annually beyond offsetting other gains. The expected-value math only favors holding when your conviction in the stock is high enough to justify carrying concentrated single-name risk that you would never assemble by buying shares outright with after-tax cash. Framed that way, the question stops being “what’s my tax rate?” and becomes “would I buy this much of this stock today?” The interaction between vest income and California’s rate structure specifically is why the state’s treatment gets its own analysis in the breakdown of why California RSU tax runs so high.

Methodology

What this means for a $150k+ household

At $150k+, RSU income almost never lands in a low bracket — it stacks on a salary that has already pushed you into the 32%, 35%, or 37% federal tier, and that bracket placement is what makes the vest expensive. The first decision is not whether to hold; it is whether your withholding covers the actual rate. Employers typically withhold federal tax on RSU vests at the 22% supplemental flat rate, which is below the marginal rate of any top-bracket earner. The gap between 22% withheld and 37%-plus owed is a quarterly-estimated-tax problem that surprises high earners every April.

The hold-versus-sell threshold for this income level turns on concentration, not conviction alone. If vested RSUs already represent a large share of liquid net worth, the tax saving from holding to LTCG rates is rarely worth the single-stock risk — selling at vest and diversifying is the disciplined default, and the tax cost of doing so is zero because basis equals the price you were just taxed on. Holding makes sense in the narrower case where the position is small relative to your portfolio, your taxable income leaves room below the NIIT and top LTCG thresholds, and you would genuinely buy more of the stock with cash. For households weighing this alongside ISO exercises, IPO grants, or ESPP purchases, the full sequencing belongs in a single plan rather than event by event; the broader framework sits in the equity compensation tax guide, and the trade-offs between option types in the comparison of ISO versus NSO tax cost. For anyone whose grants vest around a liquidity event, the distinct mechanics in an equity award at IPO change the withholding and timing calculus enough to model separately.