By Kevin Luu, Co-Founder and Chief Learning Officer. Reviewed on 2026-09-30.
A double-trigger RSU is a restricted stock unit that pays out only after two conditions are both met: a time-based vesting schedule (the first trigger) and a liquidity event such as an IPO or an acquisition (the second trigger). Until both happen, you own no shares and owe no tax. When the second trigger fires, every unit that has already time-vested is delivered and taxed at once as wages.
The same phrase, “double-trigger vesting,” also describes a different clause: acceleration of unvested equity if the company is acquired and you then lose your job. This guide explains both, because many senior employees at private and recently acquired companies hold grants that contain both.
The two meanings of “double trigger”
| Double-trigger settlement (private company RSUs) | Double-trigger acceleration (change in control) | |
|---|---|---|
| Trigger 1 | Time-based vesting (for example, quarterly over four years) | The company is acquired (a “change in control”) |
| Trigger 2 | A liquidity event: IPO or sale of the company | You are terminated without cause, or resign for “good reason,” within a set window after the deal |
| What it does | Delays delivery and tax until shares can actually be sold | Vests some or all of your unvested equity early |
| Who usually has it | Most RSU holders at venture-backed private companies | Executives and senior hires; sometimes the whole company |
| Where to find it | RSU grant agreement and equity plan | Offer letter, executive severance plan or grant agreement |
The single-trigger alternatives are simpler. A single-trigger RSU at a public company settles as soon as it time-vests. Single-trigger acceleration vests unvested equity at the deal close, whether or not you keep your job. Buyers dislike single-trigger acceleration because it removes the reason for key people to stay, which is why double-trigger is now the common design.
Why private companies use double-trigger RSUs
An RSU is an unfunded promise to deliver shares later. Under Treasury Regulation §1.83-3(e) a promise like that is not “property,” so nothing is taxed at grant and a Section 83(b) election is not available for RSUs (Treas. Reg. §1.83-3). Tax arises when shares are delivered.
If a private company delivered shares at each time-vest date, employees would owe ordinary income tax on stock they cannot sell. The liquidity condition fixes that. Because the units can still be forfeited until the liquidity event occurs, the plan is generally designed to fit the “short-term deferral” rules for deferred compensation, which require payment shortly after the risk of forfeiture lapses (Treas. Reg. §1.409A-1(b)(4)). The practical effect for you: no tax on paper wealth, then a large tax bill in the year the company goes public or is sold.
The trade-off is an expiration date. Most double-trigger RSU plans state a fixed term. If no IPO or sale happens before it ends, time-vested units can lapse worthless. Some companies have extended terms or switched to annual settlement before the deadline, but that is a company decision, not a right. Read your plan for three things: the definition of the liquidity event, the expiration date, and what happens to time-vested units if you leave before the event. For the wider picture of private company grants, see how RSUs work at a private company.
How double-trigger RSUs are taxed when the second trigger fires
At settlement, the fair market value of the delivered shares on the delivery date is wage income on your W-2. It is subject to federal income tax, Medicare, Social Security up to the wage base, and state payroll and income tax. Anything the shares gain after delivery is a capital gain when you sell.
- Federal withholding. For 2026 employers typically withhold 22% on supplemental wages, and must withhold 37% on supplemental wages above $1,000,000 in the calendar year (IRS Publication 15). A household in the 35% or 37% bracket usually still owes more in April.
- Medicare. 1.45% with no cap, plus the 0.9% Additional Medicare Tax once a married couple’s combined wages pass $250,000 for 2026.
- Social Security. 6.2% only up to the $184,500 wage base for 2026, which most readers of this page pass on salary alone.
- California. Ordinary income rates up to 13.3% (12.3% plus the 1% Behavioral Health Services Tax on taxable income over $1,000,000, 2025 schedules), plus 1.3% State Disability Insurance on all wages for 2026 with no cap (FTB 2025 rate schedules, EDD).
- Washington. No tax on wages in 2026, but the WA Cares premium of 0.58% applies to all wages with no cap (WA Cares Fund).
Lockups do not change the timing. If your units settle on IPO day and a lockup stops you selling for months, the tax is still based on the IPO-day value. If the stock falls before you can sell, you have a capital loss, which offsets only a limited amount of wage income each year.
Worked example: an acquisition with both kinds of double trigger
Assumptions (illustrative, rounded): a married couple in San Jose filing jointly. She is a product director at a private software company earning $450,000; he is a physician earning $350,000. Household wages $800,000, about $767,800 of federal taxable income after the 2026 standard deduction of $32,200, and an assumed $790,000 of California taxable income. Their two children are 4 and 7.
She holds 30,000 RSUs. 20,000 have time-vested and are waiting for a liquidity event. In 2026 a public company buys her employer for $40 a share.
Trigger two on the vested units: $800,000 of new wages
- Federal income tax. 20,000 x $40 = $800,000 of extra wages. Their taxable income was already $900 below the 37% bracket, which starts at $768,700 for 2026, so almost all of it is taxed at 37%: about $296,000.
- Federal withholding. At the 22% supplemental rate, the employer withholds $176,000. Gap: about $120,000.
- Medicare. 2.35% x $800,000 = $18,800. No added Social Security, because her salary already passed $184,500.
- California. Using the 2025 schedules on top of $790,000 of taxable income: about $96,300, including $5,900 of the 1% tax on income above $1,000,000. SDI at 1.3% adds $10,400.
- Total. About $421,500, or roughly 53% of the $800,000.
The same family living in Bellevue would owe about $296,000 federal, $18,800 Medicare and $4,640 WA Cares: roughly $319,400, or about 40%. Washington’s new 9.9% income tax on AGI above $1,000,000 starts in 2028, so a settlement in 2028 or later would look different (WA Department of Revenue).
Trigger two on the unvested units: the acceleration clause
Her other 10,000 RSUs were unvested at closing. The buyer converts them into buyer RSUs worth $400,000, continuing on the old schedule. Her offer letter has double-trigger acceleration: if she is terminated without cause within 12 months after closing, all of them vest.
If the buyer eliminates her role in month six, and that still falls in 2026, $400,000 vests on her termination date. In California, at a combined margin of close to 54% (37% federal, 2.35% Medicare, 12.3% plus 1% state income tax, 1.3% SDI), that adds about $215,800 of tax in the same year, and the federal withholding on it can again fall well short of that. Her salary stops, but the tax bill for that year is the largest the family has ever had.
The decisions double-trigger holders actually face
- Cash for the tax gap. In the example, the family needs about $120,000 extra for federal tax, plus a state shortfall. Set it aside from the shares as soon as you can sell, or make an estimated payment for the quarter of settlement to limit underpayment penalties. Our guide to withhold to cover versus sell to cover explains how the shares for tax are taken.
- Concentration. After settlement, one company’s stock may be most of the family’s net worth. Decide in advance what share of the position you will sell when the lockup ends and write the rule down.
- Stock or cash in the deal. In an acquisition, cash consideration is simply taxable wages for RSUs. Buyer stock carries the same concentration problem in a new company. See what happens to your stock when your company is sold.
- Negotiating acceleration. If you are joining a private company as a senior hire, double-trigger acceleration is often negotiable in the offer letter. Ask how “good reason” is defined (a cut in pay, title or a forced relocation usually counts) and how long the protection window lasts.
- Stock options too. Acceleration clauses usually cover options as well as RSUs. If accelerated incentive stock options make more than $100,000 of stock (valued at grant) first exercisable in one year, the excess is treated as nonqualified options (IRC §422(d)).
- Executive parachute rules. For officers and the most highly paid employees, accelerated equity counts toward the “golden parachute” limits. Payments over the limit can lose the company’s deduction and carry a 20% excise tax for the employee (IRC §4999). If you are in that group, ask the company for its 280G calculation before the deal closes.
Common mistakes
- Treating time-vested double-trigger units as owned. Until the liquidity event, they can expire or be forfeited if you leave.
- Assuming 22% withholding covers the tax. At this income it typically covers less than half of the combined federal and state cost in California.
- Waiting for the lockup to end before planning. The tax is fixed by the settlement-day price, not the price you sell at.
- Reading only the grant agreement. Acceleration terms often sit in the offer letter or a separate severance plan.
What to write down for your kids
A liquidity event can change a family’s balance sheet in a single day. Children under 12 will not remember the IPO, but they will grow up with its results. A one-page note on what you did with the proceeds (how much you kept in the company, what you paid in tax, what you set aside for their education or for giving) gives them the reasoning, not just the money. Conversations fade. Documentation compounds.
Frequently asked questions
Do double-trigger RSUs expire?
Often, yes. Most private company plans set a fixed term, and time-vested units that have not settled when it ends can lapse. Companies sometimes extend the term or settle units early, usually before a planned IPO, but you cannot count on it. Check the expiration date in your plan document and put it on the family calendar with the vesting dates.
What happens to double-trigger RSUs if I leave before the IPO?
It depends on the plan. Some let you keep time-vested units until the liquidity event, so you can owe tax years after you left. Others forfeit them at departure or after a short window. This single term can be worth more than a year of salary, so read it before you resign.
Is double-trigger acceleration the same as a double-trigger RSU?
No. A double-trigger RSU delays settlement until a liquidity event. Double-trigger acceleration speeds up vesting if the company is acquired and you are then let go without cause or leave for good reason. One grant can contain both, and they are taxed the same way: as wages when shares are delivered.
Next step
Pull your grant agreement, plan document and offer letter, and note four things: the liquidity event definition, the expiration date, the leaving-early rule and any acceleration clause. If you want help modelling the tax year and the sale plan, our tax management team can walk through it as part of a Tax & Wealth Assessment.
This is general education, and the right move depends on the family’s full picture.
Kevin has advised high-income W-2 tech and biotech families since 2015, and leads the education-first Age Five Family Office from Brea, California.
Connect on LinkedIn → · About KevinThis is part of how we approach Tax Management for high-income W-2 families at Bright Advisers.
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