Vested equity is owned outright and must be addressed in the acquisition — typically cashed out, rolled into acquirer equity, or assumed. Unvested equity is contingent on continued employment and the acquirer has full discretion over its treatment: acceleration, assumption on the existing schedule, replacement with new acquirer equity, or cancellation. The treatment of unvested equity is one of the most negotiated elements of any acquisition affecting employee economics.
Vested equity is generally treated as an economic asset in the transaction. The holder participates in the merger proceeds as a stockholder or option holder, subject to the capital structure waterfall and any deal-specific adjustments. Unvested equity is a compensation arrangement. It has not been earned, and what happens to it is determined by the negotiation between the target company and the acquirer — not by the employee individually.
The dividing line between vested and unvested, and the question of whether vested units have been delivered as shares, are the two analytical starting points for any employee equity analysis in a pending deal.
Vested common stock in an all-cash acquisition is paid out at the per-share merger consideration, subject to the liquidation waterfall. Whether common stockholders receive anything depends on whether acquisition proceeds exceed the aggregate preferred liquidation preferences. If the deal includes escrow holdbacks, a portion of every stockholder's proceeds is deferred and subject to potential indemnification claims.
In a cash acquisition, vested common stock is cashed out at the per-share merger consideration. Three issues complicate this analysis:
Common stock sits below preferred stock. Preferred stockholders — venture investors — receive their liquidation preferences before common stockholders receive any proceeds. If the deal price does not materially exceed the total preferred liquidation preference stack, common stockholders may receive little or nothing. The headline acquisition price is not the relevant number; the relevant number is what remains for common after preferred is made whole.
Standard M&A practice involves holding back a portion of merger consideration — typically 10 to 15 percent — in escrow for 12 to 18 months for indemnification purposes. Employees participating in the common stock waterfall have a pro-rata share withheld. Tax is generally owed in the year of the deal on the full gross amount, including escrowed proceeds not yet received. If escrow is later reduced by indemnification claims, the employee may recognize a loss in the year of resolution — but that is a future-year deduction, not a reduction of the current-year tax liability.
Vested non-qualified stock options (NSOs) are cashed out as the spread between the exercise price and the per-share acquisition consideration, net of ordinary income taxes and employment taxes. NSO holders do not receive capital gains treatment — the entire spread is taxed as ordinary compensation income. Options where the exercise price exceeds the acquisition consideration are out of the money and are cancelled for no value.
The spread on an NSO — FMV at exercise minus exercise price — is ordinary income at exercise, subject to payroll tax withholding. In a cash acquisition where unexercised NSOs are cashed out, the employee receives (merger consideration minus exercise price), and the entire spread is ordinary income withheld by the acquirer as payroll compensation.
If an NSO holder exercises shares prior to the deal and holds them until the acquisition, the exercise creates ordinary income on the spread at exercise. Any subsequent appreciation between exercise and deal price is a separate capital gain — short-term or long-term depending on the post-exercise holding period.
Vested incentive stock options (ISOs) can qualify for capital gains treatment if the employee exercises before or at the time of acquisition and holds the shares for the required ISO holding period. In cash acquisitions, ISOs are typically cashed out as the spread at the closing price, which may be treated as a disqualifying disposition triggering ordinary income tax rather than capital gains. The tax outcome for ISOs in acquisitions is highly fact-specific.
ISOs have the most favorable potential tax treatment and the most technical requirements. Key mechanics:
Underwater options — where exercise price exceeds deal consideration — are cancelled for no consideration regardless of option type.
Vested RSUs that have already settled into shares are treated as common stock in the acquisition. RSUs that are vested but unsettled may be cashed out at closing at the per-share merger consideration. The tax treatment depends on when settlement occurred — RSUs taxed at settlement are subject to ordinary income tax at that time, and subsequent proceeds from the acquisition are capital gains. Unsettled vested RSUs cashed out at closing are taxed as ordinary income at the acquisition price.
RSUs are contractual rights to receive shares, not shares themselves. When RSUs vest and shares are delivered, the full FMV of the delivered shares at delivery is ordinary income. There is no exercise, no spread — just ordinary income at delivery equal to shares delivered times stock price on delivery date.
In an acquisition:
Unvested equity is handled through: single-trigger acceleration (all unvested equity vests at closing), double-trigger acceleration (unvested equity vests only if the employee is terminated without cause within a specified post-closing window), assumption by the acquirer on the existing schedule, or cancellation with no payout. Double-trigger is the market standard for most employees; single-trigger is typically reserved for senior executives and founders.
The merger agreement controls the treatment of unvested equity. There are four standard outcomes.
The acquirer assumes unvested grants and converts them into equivalent unvested grants in the acquirer — same vesting schedule, same economic value at conversion. The employee continues vesting in the acquirer. No immediate tax event at conversion. The most common outcome in strategic acquisitions where the acquirer wants to retain the employee base.
The acquirer issues new awards replacing the existing unvested grants, potentially with a different share count and adjusted exercise price but equivalent economic value. Similar tax treatment to assumption. The mechanics are governed by Section 409A and applicable option plan rules to avoid unintended taxable events at substitution.
Unvested equity vests early in connection with the deal. Two variants:
Section 280G exposure: Acceleration of unvested equity in a change of control transaction counts as a "parachute payment" for 280G purposes. If total parachute payments to a disqualified individual exceed three times their five-year average W-2 compensation (the "base amount"), the excess is subject to a 20% excise tax paid by the employee, and the company loses the tax deduction for those amounts. The combined penalty is substantial. 280G analysis should be completed before the deal signs for any executive, founder, or employee with significant unvested equity or acceleration provisions.
Unvested grants are terminated for no consideration. Common in acquihires and distressed transactions. The employee loses unvested grants. Whether any severance or acceleration is owed depends on employment agreements, offer letters, and applicable state law. If cancellation occurs, the first analytical step is reviewing every employment-related agreement for acceleration or severance provisions that may have been triggered.
In an acquihire, the total acquisition consideration is often insufficient to pay equity holders at all, so the acquirer structures payments to employees as new hire compensation — signing bonuses and acquirer RSUs — rather than as acquisition proceeds. This means employees receive ordinary income tax treatment rather than capital gains treatment on compensation that represents the economic value of what they built, a tax disadvantage that is inherent in the acquihire structure.
In an acquihire, the acquirer's primary objective is retaining talent, not acquiring assets or business operations. Deal consideration is frequently structured as new employment arrangements — signing bonuses, retention grants, new RSU awards — rather than as acquisition consideration for equity. This is a deliberate economic and legal choice with direct tax consequences.
Retention packages are compensation, taxed as ordinary income with payroll withholding. Acquisition consideration for equity is capital gain (for long-term stock) or ordinary income (for options, as described above). Founders and employees in acquihires often receive more of their effective consideration in the ordinary income bucket than they would in a clean acquisition. The allocation between deal consideration and employment compensation is one of the most important negotiating variables in an acquihire, and it should be addressed explicitly in term sheet negotiations before the parties are deep in legal documentation.
The tax treatment of earnout payments to employees depends on how the earnout is structured. If the earnout is structured as additional purchase price — received as stockholders — the proceeds are taxed as capital gains to the extent the employee's basis permits. If the earnout is structured as employment compensation tied to continued service, it is taxed as ordinary income. Employees should understand the structure before signing any earnout agreement.
Earnout payments to former stockholders based on post-closing financial performance are generally treated as additional purchase price — capital gain in the year received, with the tax paid when the earnout is received rather than in the deal year. But if the earnout is conditioned on continued employment rather than pure company performance metrics, the IRS may recharacterize it as deferred compensation. That recharacterization converts capital gain into ordinary income. The deal documents are drafted to address this characterization, but the line between performance-based and employment-conditioned earnouts is sometimes contested in audit. Any earnout structure where payment is tied to an individual's continued employment warrants specific tax review before signing.
Employees should review their option agreements to understand the exercise period after termination, assess whether early exercise makes sense if options are unvested and the company allows it, confirm whether RSUs have been settled into shares, and request a waterfall analysis showing what their equity class will receive at the proposed acquisition price. This analysis should be done before the employee is asked to sign any acquisition-related document or employment agreement with the acquirer.
The actionable steps for employees and founders who know or suspect a deal is coming:
Analysis by Gurpreet S. Bal, Partner at Foley & Lardner LLP in Silicon Valley. Gurpreet has advised on more than 50 M&A transactions with aggregate deal value exceeding $60 billion. More at gurpreetbal.com.