A new tranche of restricted stock vests, fresh shares appear in your account, and the confirmation reads like a milestone. Then tax season arrives, and that same vest resurfaces, this time as an unexpected balance due. The shares didn’t lose value. The issue is simpler: the tax withholding applied at vest was never designed to match your actual bracket. It’s a formula, not a reflection of your financial reality.
It’s a Withholding Rate Built for Payroll Systems, Not People
On the day RSUs vest, their value becomes ordinary income. Federal law requires employers to withhold a flat 22% on the first $1 million of supplemental wages from one employer in a calendar year, and 37% on anything above that (IRS Publication 15, the 2026 Employer’s Tax Guide, Section 7).
The rate is set for every vest, at every company. It is not calibrated to your W‑2, your filing status, or the rest of your income.
For individuals whose marginal bracket sits at 22% or below, this withholding roughly aligns with what’s owed. But for most professionals receiving meaningful equity compensation, often in the 24%, 32%, or higher brackets, that flat 22% becomes a persistent shortfall that must be addressed elsewhere.
Why the Gap Compounds Instead of Staying Flat
The dynamic is straightforward: withholding is fixed, but your bracket is not.
Imagine someone in the 32% bracket with four vests per year, each worth $25,000. At a 22% withholding rate, each vest is under‑withheld by roughly $2,500. By the fourth vest, that’s $10,000 quietly accumulating, often unnoticed until the tax return is filed.
If the stock price rises, the gap widens further. A higher share price at vest creates a larger taxable event, yet the withholding rate remains unchanged.
The 22% rate is a convenience for payroll departments, not a tax calculation. It only aligns with your bracket by coincidence.
The Lever That Closes the Gap — Before April Does
The solution isn’t hoping the numbers reconcile at vest. It’s proactively shaping the withholding to match your reality.
A skilled advisor can direct additional withholding through your W‑4, specifying a dollar amount timed to land before or alongside known vesting dates. Alternatively, quarterly estimated payments can be sized precisely to the actual shortfall rather than a guess.
Either approach transforms an April surprise into a fully anticipated, fully funded obligation. The shares and sell‑to‑cover mechanics remain unchanged, what shifts is whether the cash to cover the true tax bill was set aside intentionally, in real time.
Is This Your Situation?
The test is simple: compare your marginal federal bracket to 22%.
- If you’re at or below it, the standard withholding is doing its job.
- If you’re above it, especially at 32% and higher, every vest this year has been under‑withheld by the same margin, and that margin does not reset.
The larger the equity award relative to salary, and the more the stock has appreciated since grant, the wider the gap becomes.
So the sharper question isn’t whether the withholding on the last vesting statement looked correct. It’s this:
Given your actual marginal tax bracket this year and the vests ahead, what is the true gap between what’s being withheld and what will ultimately be owed, and is it better to close it now or next April?
Disclaimer: This article is provided for educational, general information, and illustration purposes only and is not exhaustive. Diversification and/or any strategy that may be discussed does not guarantee against investment losses but are intended to help manage risk and return. If applicable, historical discussions and/or opinions are not predictive of future events. The content is presented in good faith and has been drawn from sources believed to be reliable. Nothing contained in the material constitutes tax advice, a recommendation for purchase or sale of any security, or investment advisory services. We encourage you to consult a financial planner, accountant, and/or legal counsel for advice specific to your situation. Reproduction of this material is prohibited without written permission from Martos Wealth Management, LLC, and all rights are reserved.
