Double-trigger RSUs at an IPO: What Kestrel Bay Retirement Advisors Tells Clients About the Tax Year

How much of a $2 million release lands above the 37% threshold?

For a single filer with $201,400 of other taxable income, $1,560,800 of a $2,000,000 release lands above the 37% threshold of $640,600, about 78% of the release. Hypothetical, 2026: Rafael, 55, is a divorced engineering manager at a hardware company, with a daughter in college. He has bought ESPP shares every purchase period for 15 years. His $250,000 salary, minus a $32,500 401(k) deferral (with the catch-up) and the $16,100 standard deduction, leaves $201,400 of taxable income.

His company goes public and $2,000,000 of RSUs settle. Taxable income becomes $2,201,400, and $2,201,400 minus $640,600 is $1,560,800 taxed at 37%. At that rate the slice alone costs $577,496 (0.37 × $1,560,800). The first $439,200 of the release (the $640,600 threshold minus his $201,400) fills the space below the line, which is why the table splits the release into slices.

Look at the $560,800 row: it is withheld at 22% but taxed at 37%. That row is where the April bill comes from. The last row already has 37% taken out, so it adds nothing to the shortfall.

Why do double-trigger RSUs release all at once at an IPO?

Double-trigger RSUs release together at an IPO because each grant needs two conditions, a service period and a liquidity event, and before the IPO only the second is missing. Grants from four or five years of refreshers can each have met their service requirement long ago. The day the company goes public, every one of them satisfies the second condition at once. That's how an employee who would have seen $400,000 a year vest ends up with $2,000,000 in a single year.

The income is taxed as wages when the shares settle, and the settlement date in your RSU agreement sets the tax year. Settlement can fall after the IPO date, sometimes in the next calendar year, so the date matters as much as the event. If it slips from December to January, the whole release moves into a different year with a different set of other income.

Then there's the lockup. It often bars sales for about 180 days (check your agreement), so you owe tax on shares you can't sell yet. That's a cash problem, because the withholding method decides how much cash you get. It's also a price risk, because the stock can fall while you wait.

What does flat withholding miss?

Flat withholding misses the gap between 22% and your real bracket. Federal withholding on supplemental wages is 22% up to $1,000,000 in the calendar year (bonuses count too) and 37% on anything above. In Rafael's case, the release's opening million splits into $439,200 below the threshold and $560,800 above it. Withholding is 15 points short on the upper slice, and 0.15 × $560,800 is $84,120.

That $84,120 is a floor, not an estimate of the whole bill. The lower slice is probably short as well, since income in the middle brackets is taxed at rates that can top 22%, but how much depends on the brackets, so check the current IRS tables. State income tax and the Medicare tax come on top. Social Security tax is already done at $184,500 of wages, so Rafael's salary has covered it and the release adds none.

The beyond-$1,000,000 slice is the only layer withheld at the top rate. People see that 37% line on the pay statement and decide the job is finished. It isn't, because the first million sets most of the shortfall.

How does Kestrel Bay Retirement Advisors plan the year, step by step?

Kestrel Bay Retirement Advisors starts with the settlement terms and works toward a cash plan, because tax first means pricing the year before anyone talks about investments. Before we suggest a gift or a sale, we estimate what the whole release costs in tax. The order below is the one we use, and the pre-IPO version can only be an estimate until the date and price are known.

• Step 1: read the RSU agreement for the settlement date and whether the company sells shares to cover tax or withholds shares net, since either method sets the cash you receive.
• Step 2: before the IPO date, Kestrel Bay Retirement Advisors estimates what the whole release costs in tax as one year of income, using several share prices rather than one.
• Step 3: decide how to cover the gap: extra paycheck withholding (counted as paid evenly through the year), an estimated payment (counted when paid), or cash set aside for April.
• Step 4: after settlement, decide gifts and sales, and sell on a schedule after the lockup instead of all at once.

Donor-advised fund and estimated payments: pros and cons side by side

A donor-advised fund helps most when you already planned to give. Estimated payments help most when withholding leaves a gap you can measure. For someone like Rafael, with a daughter in college and a lot of company stock, these are the two moves that fit a single big year. Neither is free. The Donating appreciated stock page on this site covers the gift mechanics, and the trade-offs below are the ones we weigh for a release year.

We'd lean toward the estimated payment first, because the shortfall is a known number, and treat the gift as optional. A gift only makes sense if you were going to give anyway and you itemize. Giving to get a deduction you never needed is a poor trade.

• Pro: giving settled shares to a donor-advised fund avoids gains on them, because tax basis equals the settlement price, and the deduction is capped at 30% of AGI for appreciated stock with a five-year carryforward.
• Con: the gift is permanent, and how much a deduction saves at the top bracket depends on current itemizing rules, so check before assuming 37 cents per dollar.
• Pro: an estimated payment or extra withholding ends the April surprise and avoids any underpayment penalty.
• Con: if withholding already covers 110% of last year's tax (100% if last year's AGI was $150,000 or less), the penalty is not at risk, and prepaying only ties up cash.

Mistakes to avoid with an IPO release

The costliest mistake is treating the withholding as the final tax. In Rafael's case it leaves at least $84,120 due in April on top of what was withheld, before lower-bracket gaps and state tax. A person who spent the cash from a sell-to-cover or an early sale will have nothing set aside, and that turns a tax gap into a loan from the IRS.

Waiting to give until after a sale is the second one. You pay tax on gains that a gift of settled shares would have avoided, and shares can lose value while you wait: investing involves risk, including loss of principal. Assuming the lockup postpones the tax is wrong too, because the income counts on the settlement date, whether or not the lockup lets you sell.

The last mistake is holding the whole release for a rise. If the price drops, you owe tax on a value you never sold at. That's the reason we like a written sale schedule for after the lockup, which spreads the selling over several dates. A related page on this site explains how RSUs are taxed at vest and at sale, and the Concentrated stock positions page covers what to do with the shares you keep.

A checklist for the release year

Use this list once you have the grant details, and tick each line off before the settlement date. The rule we apply is to add the release to your other taxable income and subtract $640,600 (single) or $768,700 (joint) to find the slice taxed at 37%. For the part of the first $1 million of release that sits above that line, set aside 15% of it, the gap between 22% withholding and 37%.

The numbers in this article cover federal income tax only and leave out state tax, AMT and any other income. You can't finish the plan until you know the settlement date and share price, so a pre-IPO employee can only estimate.

• Settlement date and tax year confirmed from the RSU agreement.
• Cash set aside for the gap: 15% of the slice above the threshold within the first $1,000,000, plus a state and lower-bracket allowance.
• Prior-year tax checked for the 110% safe harbor against total withholding.
• A written plan for any gift (shares, amount, timing) and a sale schedule for after the lockup.

What to do this week if you expect a release

This week, gather four facts and one number. If you also hold options or an ESPP, the Equity compensation planning page on this site covers how they interact with a release year, and Roth conversion planning or tax-loss harvesting may matter once the year's income is known. Kestrel Bay Retirement Advisors can look over your estimate, and we'd rather see a rough one now than a polished one after settlement.

• Find your RSU agreement and write down the settlement terms and the lockup length.
• Add up your expected other taxable income for the year and subtract $640,600 (single) or $768,700 (joint) from the total with the release.
• Ask HR or your equity portal how taxes will be withheld at settlement, whether by net shares or sell-to-cover.
• Send a request through the contact form on kestrelbayretirement.com if you want a second set of eyes; meetings are by video or phone.