TLDR: An earnout looks like a clever compromise on price, but it is really a deferred renegotiation dressed up as a formula, and the data say most of the money promised at signing is never actually paid.
The Argument Two Sides Never Finish
Every negotiation eventually runs into the same wall. The seller believes the business is worth what it will become; the buyer will only pay for what it can prove today. Growth companies, founder-led firms and businesses coming off an unusual year are the classic cases, where historical numbers understate the story the seller wants to tell and the buyer has no reason to take that story on faith. An earnout is the mechanism both sides reach for when neither wants to walk away and neither wants to blink first on price. Instead of settling the argument at signing, the parties let the business settle it for them, paying additional consideration only if specific post-closing targets are hit.
Done well, an earnout can align incentives, keep a departing founder engaged through the transition, and let a buyer share the downside as well as the upside of an uncertain forecast. Done carelessly, it simply postpones the fight. As Delaware’s Vice Chancellor J. Travis Laster put it in a frequently cited 2009 Chancery Court opinion, an earnout often converts today’s disagreement over price into tomorrow’s litigation over the outcome.
What Actually Gets Negotiated
Underneath the term “earnout” sits a genuine structuring decision, not a boilerplate clause. The parties agree a metric, a measurement period, a target or tiered schedule, and usually a cap. Structures range from a single threshold triggering one lump payment, to tiered or linear formulas scaling the payout to performance, to milestone payments tied to a discrete event such as a product launch, a contract renewal or a regulatory approval.
The choice of metric is where buyer and seller interests genuinely diverge. Sellers tend to push for revenue-based targets, because top-line results are harder for the new owner to manipulate through cost allocation or accounting choices. Buyers generally prefer EBITDA or net income, which reflect the profitability they are actually paying for. EBITDA is frequently the compromise, since it strips out financing and tax noise while still capturing operating discipline, making it the negotiated middle ground between a seller who wants top-line credit and a buyer who wants to pay for real earnings.
What the Data Actually Show
Earnouts are becoming a bigger part of the market, not a smaller one. 24% of private-target deals outside life sciences reported an earnout in 2025, up from 19% in 2014, according to SRS Acquiom’s long-running deal terms research. In life sciences the mechanism is closer to the default than the exception: private pharmaceutical transactions have used earnouts in over 80% of deals in recent years, reflecting how binary regulatory and clinical outcomes are for that sector’s valuations.
Size and duration follow a similar split. Outside life sciences, the median earnout represented 31% of total closing consideration in 2024, with a median measurement period of 24 months. In life sciences, earnouts run much larger and much longer, with median payments around 61% of total consideration and periods often stretching three to five years or more, since clinical and regulatory milestones simply take longer to resolve than a commercial ramp-up.
The uncomfortable number sits underneath all of this: across all deals with an earnout, roughly one out of every five dollars promised actually gets paid out. Sellers who accept a headline valuation built partly on contingent consideration should treat that figure as the realistic base case, not the exception.
| Dimension | Non-life-sciences deals | Life sciences deals |
|---|---|---|
| Frequency of use | 24% of deals (2025), up from 19% in 2014 | Over 80% of deals |
| Median size of consideration | 31% of closing payments | ~61% of total consideration |
| Median measurement period | 24 months | 3-5 years or longer |
| Most common metric | Revenue, then EBITDA | Regulatory or clinical milestones |
Source: SRS Acquiom 2025 M&A Deal Terms Study and 2023 Life Sciences M&A Study, as summarised in the Harvard Law School Forum on Corporate Governance (see References).
Why So Many End Up in Front of a Judge
The rise in earnout usage has been tracked by a corresponding rise in earnout litigation. Court filings mentioning “earn-out” and “M&A” nearly doubled in the first quarter of 2023 compared with the same period a year earlier, and that figure almost certainly understates the true dispute rate, since most earnout disagreements are resolved privately rather than in open court.
Delaware’s Chancery Court has produced a steady stream of instructive rulings on where these fights start. In one closely watched case, a buyer’s post-closing integration decisions were found to have breached its obligation to use commercially reasonable efforts toward an earnout tied to a robotics platform, with the court finding fraud and awarding the seller a share of a headline earnout potential of USD 2.35 billion on top of a USD 3.4 billion upfront payment. In another, an ambiguous definition of “Company Products” turned a straightforward calculation into a multi-year contract dispute. The pattern is consistent: vague metrics, undefined “efforts” obligations, and silence on how the buyer may run the business during the earnout period create the opening for litigation. Clear drafting, not clever drafting, keeps an earnout out of court.
The Accounting Catch Most Sellers Don’t See Coming
Even a cleanly drafted earnout still has to be accounted for, and the treatment surprises many first-time sellers and buyers alike. Under both IFRS 3 for international filers and its US counterpart, ASC 805, contingent consideration must be recognised at fair value on the acquisition date and folded into total consideration for the deal, whether or not any payment is ultimately made. That valuation typically requires a Level 3 fair value model: probability-weighted scenarios for milestone-based earnouts, or option-pricing and Monte Carlo methods for earnouts with caps, tiers or acceleration features.
The classification decision made at signing then dictates what happens next. If the arrangement is classified as a liability, which is the more common outcome, it must be remeasured to fair value at every reporting period, with the change running through the buyer’s income statement, creating earnings volatility that has nothing to do with underlying trading performance and everything to do with a shifting probability estimate. For a leveraged acquirer, that volatility can flow straight into EBITDA covenant calculations if the credit agreement’s definitions were not drafted with earnout remeasurement in mind. On the IFRS side, there is a separate and equally important threshold question: whether the earnout represents consideration for the business or compensation for the seller’s continued employment, since payments that are automatically forfeited on termination are treated as a post-combination expense rather than part of the purchase price, with very different effects on goodwill and reported profitability.
What This Means for Owners and Acquirers
Treating an earnout as a way to avoid deciding what a business is worth misreads what the mechanism does. It defers part of that decision to a future date, under rules that will be tested, argued over and, in a meaningful share of cases, litigated. The structure can genuinely bridge a valuation gap that would otherwise kill a deal, but only when the metric is unambiguous, the measurement period realistic, the buyer’s operating obligations spelled out, and the accounting consequences modelled before the term sheet is signed rather than discovered at the first quarterly close.
This is precisely the work that sits between corporate finance and deal law, and it is where Neumarz spends most of its time on behalf of Swiss and European owners and acquirers: stress-testing the metric a seller is proposing, coordinating with counsel on the covenants that protect an earnout from being quietly starved post-closing, and working through the IFRS 3 and cross-border tax consequences before either side is committed. A well-built earnout can close a gap that no upfront negotiation ever would. A badly built one simply relocates the negotiation to a courtroom, years after everyone has stopped paying attention to the detail that mattered.
References
- SRS Acquiom, “M&A Earnout and Milestone Trends,” https://www.srsacquiom.com/our-insights/ma-earnout-milestone-trends/
- F. Dario de Martino, Clare O’Brien and Mara Goodman (A&O Shearman), “The Art and Science of Earn-Outs in M&A,” Harvard Law School Forum on Corporate Governance, 11 July 2025, https://corpgov.law.harvard.edu/2025/07/11/the-art-and-science-of-earn-outs-in-ma/
- KPMG, “Does your business combination agreement have ‘earnouts’?,” https://kpmg.com/us/en/articles/2022/business-combination-agreement-earnouts.html
- The McLean Group, “How Earnouts Affect Transaction Valuation: The Technical Framework Under ASC 805,” https://mcleanllc.com/earnout-accounting-asc-805-transaction-valuation/
