"The RSU Tax Trap: Why Tech Employees Keep Getting Surprise Tax Bills"

Q: How Do You Avoid a Tax Bill Surprise in April?

Four ways, in order of effectiveness.

If you work in tech, finance, biotech, or any company that pays in equity, you've probably gotten RSUs. You've probably also gotten a tax bill in April that made your stomach drop. That's not a coincidence. The way RSU withholding works is structurally broken for anyone earning above the 22% federal bracket — which is roughly anyone making more than $48,000 single or $96,000 married filing jointly (2026 brackets).

This is the single most common cause of surprise tax bills for high-income employees. Nobody explains it in your onboarding packet. HR doesn't flag it. Your paystub looks fine. And then April rolls around and you owe $12,000 you didn't know about.

Let's walk through why it happens and how to fix it.

What Happens When Your RSUs Vest?

Restricted Stock Units vest according to a schedule — typically quarterly or annually over 3-4 years. When shares vest, they're delivered to your brokerage account (usually E*TRADE, Fidelity, Schwab, or Morgan Stanley depending on your employer).

At the moment of vesting, three things happen:

1. The value of the vested shares is added to your W-2 as ordinary income. If 100 shares vest at $200/share, your W-2 shows $20,000 of additional income for that year.

2. Your employer withholds taxes — typically by selling a portion of the shares immediately to cover the tax bill (called "sell-to-cover") or by netting shares out of your grant.

3. The remaining shares are yours to hold or sell.

So far, so normal. The problem is in step 2 — specifically, the withholding rate.

Why Are RSUs Taxed Twice?

This isn't literally two taxes on the same money. But it feels that way because taxation happens at two points, and most people only mentally account for one.

Point 1 — At vest: Ordinary income tax. When shares vest, the full market value is taxed as ordinary income, just like your salary. Federal, state (if applicable), Social Security, Medicare — the whole package.

Point 2 — At sale: Capital gains tax. When you eventually sell the vested shares, any gain or loss from the vest price is a capital gain or loss. If shares vested at $200 and you sell at $250, the $50/share gain is a capital gain. Short-term (held <1 year from vest) = taxed as ordinary income. Long-term (held ≥1 year) = taxed at preferential capital gains rates. See our guide to capital gains taxes for the full rate breakdown.

The common mistake: Treating the vest as if you bought the stock with your own cash, then getting confused when you "pay taxes twice" on the gain. You didn't. The vest was income — already taxed as income. The subsequent appreciation is a separate event, taxed only once, on the gain.

What Is the 22% Withholding Trap?

This is where the surprise bills come from. IRS rules require your employer to withhold federal income tax on supplemental wages — which includes RSU vesting, bonuses, and commissions — at a flat 22% rate for amounts under $1 million per year. Above $1M in a calendar year, the supplemental rate jumps to 37%.

22% only matches your actual tax bracket if you're in the 22% bracket. For anyone in a higher bracket, you're under-withheld on every vest.

Here's what that looks like in practice (2026 single-filer brackets):

|---|---|---|---|

| 22% (income $50,401–$105,700) | 22% | 22% | 0% |

| 24% ($105,701–$201,775) | 24% | 22% | 2 points |

| 32% ($201,776–$256,225) | 32% | 22% | 10 points |

| 35% ($256,226–$640,600) | 35% | 22% | 13 points |

| 37% ($640,601+) | 37% | 22% | 15 points |

A $50,000 RSU vest for someone in the 32% bracket generates a $5,000 federal under-withholding gap — before state taxes, before Medicare surcharges, before the 3.8% Net Investment Income Tax (for high earners), and before anything else.

Multiply this across multiple vests per year, and the surprise tax bill in April can easily hit $10,000-$30,000 for a well-compensated tech employee.

This isn't a bug in your specific paystub. This is a structural feature of IRS supplemental wage rules combined with being paid in the 24%+ brackets. If you're earning enough to get meaningful RSUs, you are almost certainly under-withheld on every single vest.

How Do You Avoid a Tax Bill Surprise in April?

Four ways, in order of effectiveness.

Option 1: Increase W-2 withholding via Form W-4, Step 4(c). Add a specific extra dollar amount per paycheck. Rough math: estimate your total RSU vest value for the year, multiply by your under-withholding gap (2%, 10%, or 13% depending on bracket), divide by remaining paychecks. Enter that number on Step 4(c). See how to actually fill out your W-4 for the full form walkthrough. Simple, automatic, no separate payments.

Option 2: Make quarterly estimated tax payments. Send checks to the IRS four times a year (April 15, June 15, September 15, January 15) covering the under-withheld amount. More work than adjusting W-4, but useful if you prefer to keep your paycheck stable and handle taxes separately. Use IRS Form 1040-ES.

Option 3: Ask for voluntary additional withholding on the vest itself. Some employers' equity platforms (ETRADE, Fidelity, Schwab Stock Plan Services) let you elect to withhold more than* the default 22% on vests. Check your platform's supplemental withholding election. Not universal, but worth checking.

Option 4: Just pay the bill in April. Set aside money in a separate savings account each time an RSU vests. When taxes come due, the money is already there. The downside: the IRS charges an underpayment penalty if your withholding falls below the safe harbor (generally 100% of last year's tax liability or 110% if your prior AGI was >$150,000). For most RSU earners, this penalty is real.

The right answer for most people: Option 1. Fix your W-4 once, forget about it, handle small adjustments at tax time.

Should You Sell RSUs as They Vest?

This is one of the most-asked questions in equity comp, and the honest framework is cleaner than most people realize.

Reframe the question. When shares vest, you've already paid ordinary income tax on them. They're equivalent to cash in your brokerage account that happens to be in your employer's stock. So the real question isn't "should I sell my RSUs?" It's "would I take this week's paycheck and buy a single stock — specifically my employer's stock?"

If the answer is no — and for most people on diversification grounds alone, it should be — then you should sell the RSUs as they vest and reinvest the proceeds in a diversified portfolio. This is called the "sell and diversify" default.

The concentration risk nobody talks about. When I was running diligence on acquisitions, we flagged management teams whose personal wealth was more than 50% concentrated in their own company as a risk indicator. It tells you something uncomfortable about their ability to make clear-eyed decisions about the company's future. The same lens applies to you. If your salary and your RSUs are both tied to one company, and you're holding vested RSUs in that same company, you have a three-way bet on your employer. A bad year means you lose your job, your unvested RSUs, and your investment portfolio simultaneously.

When holding makes sense: You have strong conviction in the stock that goes beyond employee optimism, you already have a diversified portfolio outside the RSUs, and you can afford the tax and concentration risk. Some tech employees at pre-IPO or rapidly growing companies have made life-changing money by holding. Most haven't. For every Apple employee who held 20 years, there's an Enron, WeWork, or Peloton employee who didn't.

The practical default: Sell immediately at vest, take the proceeds, put them in a diversified portfolio. Any gain from holding is a separate investment decision, and you probably wouldn't buy your employer's stock with cash — so don't effectively buy it by holding.

What's the Bottom Line?

RSUs are taxed at vest (ordinary income) and again at sale (capital gains on the subsequent appreciation only — not a second tax on the same income). The 22% flat withholding on vests is correct for people in the 22% bracket and systematically wrong for everyone above it. A $50,000 vest for a 32%-bracket employee under-withholds by $5,000 per vest. Multiply across a year of grants and the April tax bill can be brutal.

Fix it by updating your W-4 Step 4(c) with extra withholding, or by making quarterly estimated payments. On the holding question: treat vested RSUs as cash, ask yourself whether you'd buy that much of your employer's stock with a paycheck, and if the answer is no, sell and diversify.

This post is a starting point. A full equity compensation guide — covering ISOs, NSOs, ESPPs, 83(b) elections, AMT, and the interaction between grant types — is coming as a dedicated web guide. For now, if you're only receiving RSUs, the guidance above covers 90% of what you need.

Not sure if your equity setup is helping or hurting your overall financial health? The Pulse evaluates your full picture across 5 dimensions in 3 minutes — including concentration risk. Free, no sign-up.