Most sell side bankers fight on price. Then they accept a generic earnout structure and lose 30 percent of the deal in the next 36 months.

That math is real. Per SRS Acquiom multi-year deal terms studies, realized earnout payouts in lower middle market deals average 50 to 70 percent of the maximum headline. The variance inside that range is driven almost entirely by the structure choice and the clause language. Same headline, different cash in the seller's pocket.

This post is a practitioner-grade walkthrough of the four common earnout structures, when to use each, and the four phrases buyers slip into earnout clauses that quietly gut the payout.

Why earnouts matter more than sellers think

Earnouts appear in roughly one in four LMM deals. They show up most in services, SaaS, healthcare, and any business where future performance is hard to underwrite from the historicals alone. The seller wants a higher headline; the buyer wants risk transfer. The earnout is the compromise that bridges the gap.

Two facts most sellers underweight:

Fact 1: realistic payout is 50 to 70 percent of max. The headline number on a press release is a marketing figure. The seller almost never gets 100 percent of an earnout. Plan around the realistic payout when comparing offers.

Fact 2: structure changes the realized payout by 30+ percentage points. A milestone earnout pays out at materially different rates than an EBITDA earnout, even on the same business. The choice is not cosmetic.

This means the right time to fight on the earnout is during the LOI, not during the definitives. Once you have signed an exclusivity period with a vague earnout, the buyer holds the pen.

The four structures

Revenue earnout

A revenue-based earnout pays out based on top-line growth over a measurement period. Common in services, SaaS, and any business where margin is volatile but revenue is reliable.

Strengths:

• Hard to manipulate because revenue numbers show up in cash receipts
• Aligns with how the seller has historically run the business
• Easier to audit than EBITDA

Weaknesses:

• Channel stuffing risk: buyer-controlled sales motion can pull revenue forward or push it back
• Can be diluted by buyer-driven business changes (acquisitions, pricing changes, channel shifts)

When to choose: services, SaaS, recurring revenue businesses where the seller's growth thesis is the primary value.

EBITDA earnout

An EBITDA-based earnout pays out based on a profitability metric. Common in industrials, distribution, and traditional middle market deals.

Strengths:

• Captures buyer investment in operations
• Better aligns with valuation multiples used by buyers

Weaknesses:

• High manipulation risk: buyer can reallocate corporate overhead into the target's P&L, defer investment, or accelerate expenses
• Disputes are common: "consistent with past practice" gets stretched to fit the buyer's preferences

When to choose: only when the seller has audit rights, fixed cost allocations are pinned in the agreement, and the measurement methodology is defined down to the line item.

Milestone earnout

A milestone earnout pays out based on binary or step-function events: regulatory approval, contract signed, integration complete, customer migration done.

Strengths:

• Hardest to manipulate because outcomes are objectively measurable
• Highest realized payout rate in practitioner data (often 75-85 percent of max)
• Reduces dispute risk because the test is binary

Weaknesses:

• Requires events that are reasonably under the seller's control
• Can be event-driven rather than time-driven, so cash timing is harder to predict

When to choose: healthcare, R&D-heavy businesses, integration-dependent deals, anything where there is a discrete future event that the seller can credibly drive.

Hybrid earnout

A hybrid earnout combines two of the above (commonly revenue plus EBITDA, or milestone plus revenue). Common in larger LMM deals where the buyer wants both growth and profitability discipline.

Strengths:

• Balances growth incentives with margin discipline
• Reduces single-metric manipulation risk
• Allows staggered payments

Weaknesses:

• Complexity invites disputes about weighting
• Document needs to be airtight on both metrics

When to choose: most LMM deals over $20M with material earnouts, when both seller and buyer want to hedge.

The 30 percent rule

This is the practitioner heuristic that decides how much energy to spend on the earnout structure during negotiation:

• Earnout less than 10 percent of total consideration: structure is a footnote. Don't fight on it. Negotiate the price and the working capital.
• Earnout 10 to 30 percent of total: structure matters. Pin down measurement methodology, audit rights, acceleration triggers, and dispute resolution.
• Earnout greater than 30 percent of total: structure is the deal. Spend more time on the earnout schedule than on the price.

The boundary is not arbitrary. Below 10 percent, the structure can swing a few percentage points but the dollar impact is small. Above 30 percent, structure decisions can move 7-figure outcomes.

The four phrases that gut earnouts

Buyers draft the LOI. The LOI tends to use language that looks innocuous but consistently favors the calculating party (which is the buyer). These four phrases appear in nearly every buyer-drafted earnout clause:

"Calculated by Buyer"

Reads like an admin detail. In practice, it removes the seller's audit right unless the rest of the clause restores it. If the buyer calculates and the seller has no audit access, the buyer wins every dispute by default.

Rewrite: "Calculated by Buyer in accordance with attached Schedule X.X. Seller has 30-day audit right on the calculation. Disputes to a neutral accountant whose decision is binding."

"Consistent with past practice"

Looks fair. It is undefined. Past practice on cost allocation? Past practice on revenue recognition? Past practice on capital expenditures? Each interpretation moves the EBITDA number by hundreds of thousands of dollars.

Rewrite: Define "past practice" by attaching the specific accounting policies, cost allocation methodology, and capitalization thresholds the seller used in the trailing 12 months.

"In Buyer's reasonable discretion"

This phrase appears in earnout clauses about acceleration triggers, materiality determinations, and methodology choices. It hands the tiebreaker to the buyer in any subjective dispute. In arbitration, buyers prevail in roughly four out of five disputes that hinge on "reasonable discretion" language.

Rewrite: Replace with specific, objective standards. If the standard cannot be made objective, replace "Buyer's reasonable discretion" with "good faith determination subject to the dispute resolution mechanic in Section X."

Three-year measurement period

Long measurement periods favor the buyer. They give more time for changes in the business, in the buyer's strategy, in the market, all of which can suppress the earnout calculation. Three years is industry default in many sectors but it is not seller-favorable.

Rewrite: Pull to 12 to 18 months unless the deal economics specifically require longer (for example, regulatory milestones).

What a strong earnout clause looks like

Take the weak version most buyer-drafted LOIs include:

Now the rewrite:

Same structure, very different outcome.

Where to spend negotiation energy

If the deal economics put the earnout above 30 percent of total consideration, spend more time on the earnout schedule than on the headline price. Practitioners who do this consistently capture 15 to 25 percent more in realized payout than peers who fight on price and accept default earnout language.

The earnout schedule is where the deal actually pays out. The headline is what gets in the press release.

Tools and references

The full Earnout Structuring Matrix (4-page PDF reference) is free at /resources/earnout-structuring-matrix. It includes the full structure-by-deal-type matrix, sample clause language for each of the four structures, and a worked example of the 30 percent rule on a $30M deal.

If the deal includes a working capital adjustment alongside the earnout, the Working Capital Calculator provides the methodology template that should be attached to the LOI as a schedule.

For LOI clause-level drafting beyond the earnout, see the LOI Checklist.

Bottom line

Earnouts pay 50 to 70 percent of max in LMM deals. The structure decides which end. Pick the right structure for the deal type. Lock the measurement methodology in the LOI. Strike the four phrases buyers slip in. Above 30 percent of total consideration, the earnout schedule is the deal.

Sellers don't pay for advice. They pay for control. Earnout structure is where the most control gets given away.