Earn-out structures: how deferred consideration actually works in M&A deals

Earn-outs sit at the intersection of valuation disagreement and deal ambition. The concept sounds simple: part of the purchase price is deferred and paid only if the acquired business hits certain targets after closing. In practice, earn-outs generate more post-closing litigation than almost any other deal term. Understanding why requires going beneath the headline structure into the actual mechanics.

Why earn-outs matter for CFOs specifically

A CFO on either side of an M&A transaction carries a distinct burden here. On the buy side, you are engineering a payment structure that must be integrated into financing models, accounting treatment, and management incentive plans simultaneously. On the sell side, you are often being asked to accept that a meaningful portion of your proceeds depend on targets you may no longer fully control once the acquirer takes over.

The accounting dimension alone justifies deep attention. Under IFRS 3 and ASC 805, contingent consideration (the earn-out) must be measured at fair value on the acquisition date and remeasured at each subsequent reporting period. Changes in that fair value flow through the income statement, not through goodwill. This means an earn-out that performs better or worse than modelled at signing will create P&L volatility that has nothing to do with underlying operations. Many CFOs discover this dynamic after the fact, which is the wrong moment.

Beyond accounting, earn-outs directly affect leverage ratios and debt covenants. If you have financed the acquisition with a leveraged loan or a revolving credit facility, the lender's calculation of total debt may or may not include contingent consideration depending on how probability-weighted the earn-out is. Getting that wrong at the term sheet stage creates renegotiation risk later.

How earn-outs actually work: the mechanics

The basic structure involves three negotiated components: the metric, the measurement period, and the payout formula.

The metric is the variable that triggers payment. Revenue is the most common choice because it is hard to manipulate and easy to audit. EBITDAEBITDAEBITDA (Earnings Before Interest, Taxes, Depreciation, and Amortization) measures a company's operating profitability before financing and accounting decisions, used to compare core performance across firms.View full definition → is frequently preferred by sellers who want to capture profitability, but it creates immediate problems post-closing because the acquirer controls cost allocation, shared service charges, and management fees, all of which can compress EBITDA without technically breaching any agreement. Milestone-based earn-outs (FDA approval, a signed contract with a named customer, completion of a software integration) work well in life sciences and SaaS but require extremely precise drafting.

The measurement period typically runs one to three years. Beyond three years, earn-outs become difficult to enforce and tend to create ongoing management distraction. Shorter periods of 12 months work when the trigger is a discrete event rather than cumulative financial performance.

The payout formula can be binary (hit the target, receive the payment), linear (earn-out scales proportionally between a floor and a cap), or tiered. A tiered structure might look like this: no payment if revenue falls below 80% of target, 50 cents on the dollar between 80% and 100% of target, full payment at 100%, and an accelerator above 110%.

A concrete example: in 2019, Bristol-Myers Squibb's acquisition of Celgene included a contingent value right (a publicly traded instrument structurally similar to an earn-out) worth up to $9 per share tied to FDA approval milestones for three drugs. The CVRCVRThe percentage of visitors or prospects who complete a desired action (purchase, sign-up, contact form), calculated as conversions divided by total opportunities.View full definition → mechanism made the contingent consideration tradeable, which solved the liquidity problem for Celgene shareholders. Not every deal has that option, but the BMS-Celgene structure illustrates how milestone-based contingent consideration can close a valuation gap that pure cash or stock consideration cannot bridge.

For private deals without tradeable CVRs, the earn-out agreement must address what happens if the acquirer changes the acquired business's strategy, redirects its sales force, or decides not to invest in the product line that drives the earn-out metric. Without explicit protective covenants, sellers frequently find themselves holding a claim they cannot enforce.

When to use earn-outs and when to walk away from them

Earn-outs work best in four specific situations: when there is a genuine, quantifiable valuation gap driven by uncertainty about future performance (not just a price disagreement); when the sellers will remain as operating managers post-closing with real influence over the metric; when the metric is revenue or a specific milestone rather than an earnings figure the buyer can manipulate; and when the measurement period is short enough to stay within the sellers' planning horizon.

They work poorly when the acquired business will be immediately integrated into the buyer's existing operations. Once a target's sales team is merged into the acquirer's, its customer relationships reassigned, and its cost base restructured, the question "how did the acquired business perform?" becomes unanswerable. The earn-out metric becomes meaningless, and the dispute is almost certain.

There is also a financing dimension that gets underweighted. Acquirers using leveraged buyout structures sometimes treat earn-outs as a way to reduce the equity check at closing, effectively deferring part of the purchase price and improving their IRRIRRThe Internal Rate of Return is the discount rate that makes a project's net present value equal zero. It expresses an investment's expected annualized return.View full definition → models. This logic has a flaw: earn-out payments ranked as equity consideration do not reduce initial leverage, but they do represent a real future cash outflow that must be modelled into the debt service coverage analysis. Sponsors who underweight this sometimes find themselves refinancing at an inopportune moment precisely because the business performed well and triggered a large earn-out payment.

On the sell side, the honest tradeoff is this: an earn-out is not a premium, it is a bet. If the seller was a founder-operator who built the business over fifteen years, accepting that 30% of the purchase price depends on what happens after a new parent takes over is a significant risk transfer that should be priced accordingly. The appropriate response is either to negotiate hard on the protective covenants, push the earn-out metric toward something you control, or simply discount the earn-out to zero in your internal valuation and treat any payment as upside.

Earn-outs close deals that would otherwise collapse, and that is a genuine function. The CFO's job is to make sure the structure is financially coherent on both sides, legally defensible, and integrated correctly into the accounting and financing framework from day one. A poorly drafted earn-out that triggers litigation two years post-closing destroys more value than the valuation gap it was designed to bridge.