An earnout payment is a portion of a business acquisition’s purchase price that the seller receives only if the acquired company hits agreed-upon performance targets after the deal closes. Buyers and sellers use earnouts to bridge valuation disagreements: the buyer avoids overpaying for projections that may not pan out, and the seller keeps a shot at the full price if those projections do. How the earnout is structured drives the seller’s tax bill, the buyer’s financial statements, and the odds of a fight down the road.
How Earnouts Are Structured
Every earnout turns on three things: the performance metric, the measurement period, and the payout formula.
Financial metrics dominate. EBITDA thresholds and revenue targets are the most common because they are relatively straightforward to calculate and track. Non-financial milestones appear more often in specialized industries: FDA approval for a drug candidate, completion of a software integration, retention of a specified percentage of key customers.
The median earnout period for deals outside life sciences is about 24 months. Life sciences transactions tend to run three to five years or longer because regulatory timelines make shorter windows impractical.1Harvard Law School Forum on Corporate Governance. The Art and Science of Earn-Outs in M&A Shorter periods keep things simple and reduce the surface area for disputes. Longer periods give strategic initiatives time to bear fruit but introduce more opportunities for the parties to disagree about what happened and why.
Payout formulas usually avoid all-or-nothing outcomes. A tiered structure might pay a percentage of the maximum earnout for reaching 80% of the target, with escalating payouts for hitting 100% or exceeding it. That gives the seller meaningful upside while softening the blow of a near miss. The agreement also sets a cap on the maximum total earnout and a floor below which nothing pays at all.
Purchase Price or Compensation? The Threshold Tax Question
Before any other tax question matters, the IRS needs to know what the earnout actually is: additional purchase price for the business, or compensation for services the seller provides after closing. The answer drives nearly every downstream consequence for both parties, and the IRS looks at the facts and circumstances of each deal rather than accepting whatever label the parties put on it.
Factors that push toward purchase price treatment include an earnout that was proposed to bridge a valuation gap in negotiations, payments that are proportional to the seller’s equity ownership, and a seller who already receives a reasonable salary for any post-closing work. The IRS leans toward compensation treatment when the seller must perform specific services to receive payment, when payments go disproportionately to certain shareholders (typically the ones staying on to run the business), or when the earnout formula tracks individual performance rather than overall business results.
The stakes are substantial. Sellers want purchase price treatment because the payments qualify for long-term capital gains rates and avoid employment taxes. Buyers prefer compensation treatment because they get a tax deduction for the payment. When an earnout is recharacterized as compensation, the seller faces ordinary income rates plus payroll taxes, and two additional traps open up.
The first is Section 409A. A compensation-characterized earnout generally counts as deferred compensation because the seller has a legally binding right to a payment that may come in a later tax year. If the arrangement doesn’t fit the “short-term deferral” exception (payment within two and a half months after the end of the year the target is met) or satisfy 409A’s distribution timing rules from the start, the seller faces immediate taxation of the deferred amounts, a 20% penalty tax, and an interest charge. Retroactive fixes are extremely limited.
The second is Section 280G. When a compensation-characterized earnout is contingent on a change in corporate ownership, it can be swept into the golden parachute rules. If total parachute payments to a “disqualified individual” exceed three times their base compensation, the excess becomes an “excess parachute payment.” The buyer loses its deduction for the excess amount, and the seller owes a 20% excise tax on top of regular income tax.2eCFR. 26 CFR 1.280G-1 – Golden Parachute Payments Deals involving sellers who are also senior executives need to model the 280G math before finalizing the earnout.
What the Seller Pays in Tax
When the earnout qualifies as additional purchase price, the seller’s goal is long-term capital gains treatment. Payments received as consideration for the sale of stock or business assets generally qualify. For 2026, long-term capital gains rates are 0%, 15%, or 20% depending on taxable income, with the 20% rate starting at $545,500 for single filers and $613,700 for joint filers. Ordinary income rates run as high as 39.6% in 2026, so the gap matters.
Imputed Interest
Even when the earnout clearly counts as purchase price, a portion of each deferred payment gets recharacterized as interest income and taxed at ordinary rates. Under IRC Section 483, any payment due more than six months after the sale date is subject to imputed interest rules when some payments under the contract are due more than one year after the sale.3Office of the Law Revision Counsel. 26 USC 483 – Interest on Certain Deferred Payments The logic: a dollar received two years from now is worth less than a dollar today, and the code treats the difference as interest whether the parties call it that or not.
The minimum rate the IRS requires is the applicable federal rate, published monthly.4Internal Revenue Service. Applicable Federal Rates If the contract’s stated rate falls below the AFR or states no rate at all, Section 483 recharacterizes enough of each payment to bring the effective rate up. Sellers can shrink this ordinary-income slice by negotiating interest into the earnout agreement at or above the AFR from the start.
Installment Sale Reporting
Earnouts where the total price is uncertain at closing are treated as contingent payment installment sales under IRC Section 453.5Office of the Law Revision Counsel. 26 USC 453 – Installment Method How the seller recovers basis depends on how the agreement is written:
- If the agreement specifies a maximum price, the seller calculates gain based on that maximum and recovers basis proportionally as payments arrive. If the earnout ultimately pays less than the maximum, the seller recognizes a loss when the contingency is resolved.
- If the agreement sets a fixed payment period but no maximum price, basis is recovered in equal annual installments over the payment period.
- If the agreement has neither, the IRS requires basis recovery in equal annual increments over 15 years from the date of sale. The IRS scrutinizes these arrangements closely and may question whether a sale has actually occurred.6eCFR. 26 CFR 15a.453-1 – Installment Method Reporting for Sales of Real Property and Casual Sales of Personal Property
The 15-year default can create a real cash flow problem, because the seller may owe tax on payments well before recovering enough basis to offset the gain. Push for either a stated maximum price or a fixed earnout period.
The 3.8% Surtax
Sellers whose modified adjusted gross income exceeds certain thresholds owe an additional 3.8% net investment income tax on their capital gains from the earnout. The thresholds are $250,000 for married couples filing jointly and $200,000 for single filers.7Internal Revenue Service. Net Investment Income Tax In a large transaction, this surtax is essentially unavoidable and should sit in the after-tax model from day one.
What the Buyer Pays in Tax
The buyer’s tax treatment mirrors the characterization question. If the earnout is additional purchase price, the buyer gets no current deduction. The payments increase the buyer’s cost basis in the acquired assets or stock, which may yield depreciation or amortization deductions over time but provides no immediate tax benefit. If the earnout is compensation, the buyer deducts the payments as a business expense in the year paid, subject to the Section 280G limits and payroll tax withholding.
That sets up a natural tension. The seller’s preferred characterization is the buyer’s worst case, and vice versa. Sophisticated deals address this directly, sometimes adjusting the headline purchase price to account for the tax consequences each side will bear under the agreed treatment.
What the Earnout Does to the Buyer’s Books
Under ASC 805, the buyer must recognize the earnout as part of acquisition-date consideration and measure it at fair value on the closing date, regardless of how likely the payout is at the time. The initial fair value typically comes from a probability-weighted model that estimates payments under different scenarios and discounts them to present value.
What happens after closing depends on classification, which is dictated by the nature of the arrangement rather than preference.
- Liability-classified earnouts, which cover most arrangements, are remeasured to fair value at each reporting date, with changes flowing through the income statement. If the business is trending above expectations, the buyer records a loss as the liability grows. If the business underperforms, the buyer records a gain. The result is earnings volatility that has nothing to do with the buyer’s core operations.8Deloitte Accounting Research Tool. Deloitte Roadmap – Business Combinations – 5.7 Contingent Consideration
- Equity-classified earnouts are recorded at fair value on the acquisition date and never remeasured. The initial amount stays on the books regardless of how the business performs, and final settlement is accounted for within equity. This avoids the income statement volatility but is less common because the rules impose strict conditions on equity classification.8Deloitte Accounting Research Tool. Deloitte Roadmap – Business Combinations – 5.7 Contingent Consideration
The liability-side volatility catches some buyers off guard. A strong quarter for the acquired business can depress the buyer’s reported earnings because the expected payout rises. Public company buyers often negotiate structures that qualify for equity classification to avoid this, though doing so limits the flexibility of the terms.
How Sellers Protect the Earnout After Closing
The seller’s fundamental vulnerability is simple. Once the deal closes, the buyer controls the business. A buyer can starve the acquired unit of resources, reassign key employees, redirect customers to other divisions, or load the unit with corporate overhead. Any of these can crater the earnout metrics without technically violating the purchase agreement, unless the seller negotiated protections in advance.
Operating Covenants
Sellers demand covenants requiring the buyer to operate the business consistent with past practice: maintaining adequate staffing, providing sufficient working capital, and continuing historical levels of investment in areas like marketing and R&D. Anti-manipulation clauses go further, explicitly prohibiting the buyer from diverting customer contracts to other business units, allocating a disproportionate share of corporate overhead to the acquired entity, or making operational decisions that benefit the broader organization at the earnout unit’s expense.
The agreement should also lock in the accounting methodology used to calculate the metrics. Without that, a buyer can depress reported EBITDA simply by changing how it accounts for revenue recognition, inventory reserves, or intercompany charges.
Information and Audit Rights
Sellers should negotiate the right to receive regular financial reports showing how the metrics are tracking. At a minimum, the buyer should deliver an earnout certificate after each measurement period detailing the revenues, expenses, and adjustments used to compute the result. The seller also needs the right to review the underlying books and records, and to engage an independent auditor at the seller’s expense if something looks off. Without these rights, the seller depends entirely on the buyer’s good faith in reporting the numbers.
Acceleration Clauses
If the buyer resells the acquired business, goes through its own change of control, or files for bankruptcy before the earnout period ends, the seller’s ability to earn the contingent payment may vanish. Acceleration clauses make the earnout immediately payable at the maximum amount upon triggers like a subsequent sale, a material breach of the operating covenants, or the termination of selling shareholders from their management roles. The buyer’s willingness to accept them often reveals how seriously it intends to honor the earnout’s spirit.
Payment Security
An earnout is only worth something if the buyer can actually pay when the time comes. Sellers in larger transactions sometimes negotiate for the obligation to be secured by an escrow account, a letter of credit, or a holdback from the closing proceeds. Buyers resist these mechanisms because they tie up capital. At a minimum, the purchase agreement should include representations about the buyer’s financial capacity and ensure the earnout obligation survives any subsequent restructuring of the buyer’s corporate entity.
When Earnouts End Up in Dispute
Earnout disputes are common enough that experienced M&A lawyers treat the dispute resolution mechanism as a core deal term. Most agreements send disagreements over whether the targets were met to an independent accounting firm for binding determination. That is faster and cheaper than arbitration or litigation and works well when the dispute is genuinely about accounting methodology.
When the dispute goes beyond math, the seller’s recourse depends heavily on what the contract says. Courts generally enforce the plain language of the earnout provision and are reluctant to rewrite a deal that simply turned out worse than one side expected. The implied covenant of good faith and fair dealing exists as a backstop, but it is narrow. Courts treat it as a gap-filler for situations the parties genuinely didn’t anticipate, not as a way to punish a buyer for business decisions that happened to hurt the earnout.9Harvard Law School Forum on Corporate Governance. Delaware Supreme Courts Earnout Decision Reinforces Primacy of Contract and Illustrates the Limits of the Implied Covenant
Where the agreement includes an “efforts” obligation requiring the buyer to take specific steps (such as pursuing regulatory approvals with commercially reasonable efforts), courts will hold the buyer to the agreed standard, particularly when the contract itself provides a roadmap for what those efforts should look like.9Harvard Law School Forum on Corporate Governance. Delaware Supreme Courts Earnout Decision Reinforces Primacy of Contract and Illustrates the Limits of the Implied Covenant The practical takeaway: sellers cannot count on courts to fill gaps that good lawyering should have closed at signing. Every protection the seller wants belongs in the agreement, because after closing the contract is the seller’s best and often only weapon.