An earnout payment is the portion of an acquisition’s purchase price that a seller collects only if the acquired business hits agreed performance targets after closing. Buyers and sellers use earnouts to bridge valuation gaps: the buyer avoids overpaying for projections that may never materialize, and the seller keeps a shot at the full number if those projections come true. How the deal is structured drives everything downstream, including the seller’s tax rate, the buyer’s financial statements, and how much room either side has to fight later. Earnout provisions are among the most litigated terms in M&A agreements, so the details in the contract matter far more than the headline number.
How an Earnout Is Structured
Every earnout has three moving parts: 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 show up more often in specialized industries: FDA approval for a drug candidate, completion of a software integration, retention of a specified percentage of key customers through the transition.
The median earnout period outside life sciences is about 24 months. Life sciences deals 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 multiply the chances the buyer and seller will disagree about what happened and why.
Payout formulas usually avoid all-or-nothing outcomes. A tiered structure might pay a percentage of the maximum for reaching 80% of the target, with escalating payouts at 100% or above. That gives the seller meaningful upside while softening the blow of a near-miss. Agreements typically also set a cap on the maximum total earnout and a floor below which no payment triggers, giving both sides defined boundaries.
Purchase Price or Compensation? The Threshold Tax Question
Before any other tax analysis matters, the IRS needs to know what the earnout actually represents: additional purchase price for the business, or compensation for services the seller performs after closing. The answer drives nearly every downstream tax consequence for both parties, and the IRS looks at the facts and circumstances of the deal rather than accepting whatever label the parties put on it.
Factors that push toward purchase price treatment include an earnout proposed during negotiations to bridge a valuation gap, payments proportional to the seller’s equity ownership, and a reasonable salary already paid to the seller for any post-closing role. Factors pointing to compensation include a requirement that the seller perform specific services to receive payment, payments that go disproportionately to certain shareholders (typically the ones staying on to run the business), and formulas that track individual performance rather than overall business results.
The stakes are large. Sellers want purchase price treatment because payments qualify for long-term capital gains rates and avoid employment taxes entirely. Buyers prefer compensation treatment because they get a current tax deduction. When an earnout is recharacterized as compensation, the seller faces ordinary income rates plus payroll taxes, and two additional regulatory traps open up.
The first is IRC Section 409A. An earnout treated as compensation generally counts as deferred compensation, because the seller has a legally binding right to a payment that may come in a later tax year. Section 409A demands that deferred compensation be paid only on specific triggering events. An earnout that doesn’t conform from inception exposes the seller to immediate taxation of the deferred amounts, a 20% penalty tax, and an interest charge. Retroactive fixes are extremely limited, so the contract language has to be right at signing.
The second is IRC Section 280G. If the earnout is compensation-like and is contingent on a change in corporate ownership, it can be swept into the golden parachute rules. When 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 and the seller owes a 20% excise tax on top of regular income tax.2eCFR. 26 CFR 1.280G-1 – Golden Parachute Payments Any deal where the seller is also a senior executive of the target needs the 280G math modeled before the earnout is finalized.
What the Seller Pays in Tax
When the earnout qualifies as additional purchase price, the seller’s goal is long-term capital gains treatment on payments received for the sale of stock or business assets. For 2026, long-term capital gains rates are 0%, 15%, or 20% depending on taxable income, with the 20% rate kicking in at $545,500 for single filers and $613,700 for joint filers. That is considerably better than ordinary income rates, which run as high as 39.6% in 2026.
Imputed Interest on Deferred Payments
Even when the earnout clearly counts as purchase price, a portion of each deferred payment is recharacterized as interest income and taxed at ordinary rates. Under IRC Section 483, any payment due more than six months after the sale is subject to imputed interest rules if 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 is straightforward: a dollar received two years from now is worth less than a dollar today, and the tax code treats the difference as interest whether or not the parties call it that.
The minimum rate is the applicable federal rate, published monthly by the IRS.4Internal Revenue Service. Applicable Federal Rates If the contract’s stated rate is below the AFR, or if no rate is stated, Section 483 recharacterizes enough of each payment to bring the effective rate up to the AFR. Sellers can shrink this ordinary-income slice by negotiating interest into the agreement at or above the AFR from the start.
Installment Sale Basis Recovery
Earnouts where the total price remains 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 basis is recovered depends on how the agreement is drafted:
- If the agreement specifies a maximum price, the seller computes 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 there is a fixed payment period but no maximum price, basis is recovered in equal annual installments over the payment period.
- If there is neither a maximum price nor a fixed period, basis must be recovered 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 at all.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. Sellers should push for either a stated maximum price or a fixed earnout period.
Net Investment Income Tax
Sellers whose modified adjusted gross income exceeds $250,000 (joint) or $200,000 (single) owe an additional 3.8% net investment income tax on capital gains from the earnout.7Internal Revenue Service. Net Investment Income Tax In a sizable transaction this surtax is essentially unavoidable and should be built into after-tax modeling from the start.
What the Buyer Gets: Tax and Accounting
The buyer’s tax picture mirrors the characterization question. If the earnout is additional purchase price, the buyer gets no current deduction; the payments increase cost basis in the acquired assets or stock and may yield depreciation or amortization deductions over time. 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 to payroll tax withholding.
That creates natural tension in negotiations. The seller’s preferred characterization (purchase price, capital gains) is the buyer’s worst-case scenario (no deduction), and vice versa. Sophisticated deals sometimes adjust the headline purchase price to account for the tax consequences each side will bear under the agreed characterization.
Contingent Consideration Under ASC 805
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 signing. The initial fair value typically comes from a probability-weighted model that estimates potential payments under different scenarios and discounts them to present value.
What happens next depends on classification:
- Liability-classified earnouts, which are the majority, are remeasured to fair value at each reporting date. Changes flow through the income statement. If the business is trending above expectations, the buyer records a loss as the liability grows. If it underperforms, the buyer records a gain. That creates earnings volatility that has nothing to do with 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. That avoids the volatility, but the rules impose strict conditions on equity classification, so it is less common.8Deloitte Accounting Research Tool. Deloitte Roadmap – Business Combinations – 5.7 Contingent Consideration
The liability-classification volatility catches buyers off guard. A strong quarter for the acquired business can paradoxically depress the buyer’s reported earnings because the expected earnout payout rises. Public company buyers often negotiate for structures that qualify for equity classification, at the cost of some flexibility in the terms.
Protecting the Payment 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 breaching the purchase agreement, unless the seller negotiated protections in advance.
Operating covenants require the buyer to run the business consistent with past practice: maintain adequate staffing, provide sufficient working capital, continue 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 units, allocating disproportionate 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 earnout metrics, because without that, a buyer can depress reported EBITDA simply by changing how it accounts for revenue recognition, inventory reserves, or intercompany charges.
Information rights matter just as much. The buyer should be required to deliver an earnout certificate after each measurement period detailing the revenues, expenses, and adjustments used to compute the result. The seller should have the right to review the underlying books and records and, if something looks off, to engage an independent auditor at the seller’s expense to verify the calculation.
Acceleration clauses address what happens if the buyer resells the business, undergoes its own change of control, or files for bankruptcy before the earnout period ends. These clauses make the earnout immediately payable at the maximum amount on triggering events such as a subsequent sale, a material breach of operating covenants, or 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.
Finally, an earnout is only worth something if the buyer can actually pay when the time comes. Larger transactions sometimes secure the obligation with an escrow account, a letter of credit, or a holdback from closing proceeds. Buyers resist these because they tie up capital, so at a minimum the purchase agreement should include representations about the buyer’s financial capacity and confirm that the earnout survives any restructuring of the buyer’s corporate entity.
When Disputes Arise
Earnout disputes are common enough that experienced M&A lawyers treat the dispute resolution mechanism as a core deal term, not boilerplate. Most agreements send disagreements over whether the targets were met to an independent accounting firm for binding determination. That process is faster and cheaper than arbitration or litigation, and it works well when the dispute is genuinely about accounting methodology rather than bad faith.
When the dispute goes beyond math, the seller’s recourse depends heavily on the contract. 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 a narrow tool. 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 to achieve the earnout targets, such as pursuing regulatory approvals with commercially reasonable efforts, courts will hold the buyer to the standard the parties agreed to, 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 Every protection the seller wants needs to be written into the agreement, because after closing the contract is the seller’s best, and often only, tool.