The Earnout Trap: How Deal Structure Can Turn a $5M Sale into a $3M Tax Bill
Earnouts look like a bridge between buyer and seller — but their tax treatment can quietly convert capital gains into ordinary income. Here's what to watch for before you sign.
Written by: Gus Zuccaro
Date of publication: 09.01.2026
Table of Contents
Picture a business owner who has just negotiated the sale of a lifetime’s work: $5 million total, with $3 million paid at closing and the remaining $2 million structured as an earnout tied to revenue milestones over the following three years. The deal feels done. The hard part, negotiating price, surviving diligence, getting to signature, is behind them.
What many sellers don’t realize until well after the ink is dry is that the tax treatment of those earnout payments isn’t automatic. Depending on how the agreement is worded and what the payments are economically tied to, that $2 million can be taxed at ordinary income rates instead of capital gains rates. On a deal that size, the difference between the two can run into the hundreds of thousands of dollars, and by the time the first earnout payment arrives, it’s too late to fix.
Earnouts are a legitimate, widely used tool for closing valuation gaps in M&A. But the rules governing how the IRS characterizes and times these payments are technical, easy to get wrong, and effectively irreversible once the purchase agreement is signed. This guide walks through how earnout payments are taxed, when they slip from capital gain into ordinary income, how imputed interest rules interact with deferred payments, and what sellers can do, before signing, to protect the economics they thought they negotiated.
Key Takeaways:
- Earnout payments aren't automatically taxed as capital gains — the structure of the agreement determines the outcome. If the payment is tied to the business's performance, it generally qualifies as additional purchase price and gets capital gain treatment. If it's tied to the seller's personal performance or employment, the IRS can recharacterize it as ordinary income, at rates significantly higher than capital gains.
- Blending the earnout with an employment agreement is the most common and costly mistake. When the purchase agreement and the employment agreement aren't cleanly separated, the earnout loses its character as sale consideration. The fix is straightforward: document the earnout unambiguously as purchase price, and compensate post-close services separately at market rates under a standalone employment or consulting agreement.
- Imputed interest quietly converts part of every earnout payment into ordinary income. Even if the agreement never mentions interest, the IRS will impute it on deferred payments under Section 483 or the OID rules — and that imputed interest is always ordinary income regardless of how the rest of the gain is characterized. Building an adequate interest rate into the agreement at signing eliminates this problem before it starts.
- The installment method spreads the tax hit across years, but contingent payments come with their own complexity. Most earnouts qualify as installment sales, meaning gain is recognized as payments arrive. But because the total price isn't fixed at closing, the seller must apply one of three IRS-prescribed methods to determine how much gain to report each year — and the default method may not be the most favorable one.
- Personal goodwill is a separate issue that catches sellers off guard. When earnout payments are functionally tied to the seller maintaining client relationships or continuing to perform, they may be characterized as compensation for personal goodwill — which carries its own tax treatment and documentation requirements. "Goodwill is goodwill" is not how the IRS sees it.
- Every one of these problems is solvable, but only before the purchase agreement is signed. Once the deal closes, the structure is locked. The character of the payments, the interest treatment, the installment method election — all of it is determined by what the agreement says. The time to model the after-tax outcome under different scenarios is during negotiation, not when the first earnout check arrives.
What Is an Earnout and Why Do Deals Include Them?
The Mechanics of an Earnout
An earnout is a contingent payment structure: part of the purchase price is paid at closing, and the rest is paid later, contingent on the business hitting specific post-closing targets, such as revenue, EBITDA, or client retention. Earnouts exist because buyers and sellers frequently disagree about what a business is worth, particularly when recent growth, a new contract, or a strategic initiative hasn’t yet shown up fully in historical financials. Rather than walk away from the deal, the parties agree the seller gets paid more if the projected performance actually materializes.
Why the Tax Treatment is Complicated
Here’s the part that catches sellers off guard: the IRS does not automatically treat earnout payments as simply a deferred slice of the sale price. The character of the payment, whether it’s capital gain or ordinary income, depends on what it is economically tied to, not just on what the parties call it in the agreement. Two earnout structures that look nearly identical on paper can be taxed completely differently depending on subtle differences in drafting. This is rarely obvious to a seller reading the purchase agreement for the first time, and it’s often not obvious to buyer’s counsel either, since their priority is usually deal protection, not the seller’s tax outcome.
Capital Gain vs. Ordinary Income: The Character Problem
When Earnouts Generate Capital Gain
When an earnout payment represents additional consideration for the business itself, compensation for the value of what was sold, not for anything the seller does afterward, it’s generally treated as capital gain. If the underlying interest sold (stock, membership interest, or the business’s goodwill) was a capital asset held for more than a year, the earnout payments that represent extra purchase price take on that same capital character. This is the outcome most sellers assume they’re getting.
When Earnouts Generate Ordinary Income
The risk is recharacterization: the IRS treating what looks like purchase price as disguised compensation instead. This tends to happen in a few recurring situations:
- The seller stays on post-close, and the earnout is tied to their employment agreement rather than standing separately as purchase price.
- The milestone is tied to the seller’s personal performance, for example, the seller personally retaining certain client relationships or personally hitting a sales target, rather than to the business’s overall results.
- The agreement is ambiguous about whether the payment is additional sale consideration or compensation for services, leaving the door open for the IRS (or an auditor) to make that call unfavorably.
Once a payment is recharacterized as compensation, it’s taxed as ordinary income, and it may also be subject to payroll taxes, compounding the hit.
The Sale of Goodwill Distinction
A related and often overlooked issue is personal goodwill. Personal goodwill, the value tied to the seller’s individual relationships, reputation, and expertise, is treated as a distinct asset from the business’s own (enterprise) goodwill. When earnout payments are functionally tied to the seller maintaining those personal relationships or continuing to perform after closing, they may be characterized as compensation for personal goodwill, which carries its own tax treatment and its own documentation requirements. Sellers who assume “goodwill is goodwill” for tax purposes are often surprised here.
The Installment Method and Contingent Payment Rules
How the Installment Method Applies to Earnouts
Most earnouts qualify as installment sales under Section 453, meaning the seller recognizes gain as payments are actually received rather than all at once in the year of closing. That’s generally favorable: it spreads the tax liability across the years the cash actually arrives. But earnouts complicate this because the total selling price isn’t fixed at closing; it depends on performance that hasn’t happened yet. When the total price is contingent, the seller has to use one of three IRS-prescribed methods to figure out how much gain to recognize each year, and the method that applies by default may not be the most favorable one available.
Open Transaction Treatment
In rare cases, where the earnout is so speculative that its value truly cannot be reasonably estimated, the IRS permits “open transaction” treatment: deferring all gain recognition until the seller has fully recovered their basis in the business. This sounds attractive, but the IRS scrutinizes these claims heavily, and the bar for proving an earnout is genuinely indeterminate is high. Sellers shouldn’t assume this treatment is available just because the earnout is uncertain.
The Imputed Interest Problem
This is the piece that surprises even sophisticated sellers. When earnout payments are deferred beyond the year of sale, the tax code requires that a portion of each payment be treated as interest, under Section 483 or the original issue discount (OID) rules, even if the purchase agreement never mentions interest at all. That imputed interest is ordinary income, full stop, regardless of whether the underlying gain on the sale would otherwise have qualified for capital gains treatment. Left unaddressed, this quietly converts part of every earnout payment into ordinary income by operation of law.
Have Questions About How Your Earnout Will Actually Be Taxed?
Structuring Earnouts to Minimize Tax Risk
The good news is that most of these risks are addressable, but only in the drafting stage, before signature.
Separate the Earnout From Employment Compensation
The single most important structural decision a seller can make is ensuring the earnout is documented, unambiguously, as additional purchase price, not as compensation contingent on the seller’s continued employment. In practice, this means clean language in the purchase agreement establishing the earnout as sale consideration, paired with a separate employment or consulting agreement that pays the seller market-rate compensation for any post-close services. Blurring these two documents together is one of the most common, and costly, mistakes in earnout drafting.
Fix the Maximum Selling Price Where Possible
If the purchase agreement states a maximum possible selling price for the earnout, the seller may be able to use the simpler “maximum selling price” method under the installment sale contingent-payment regulations, rather than the more complex methods that apply when there’s no stated cap. This can meaningfully simplify gain recognition over the life of the earnout.
Address Interest Up Font
Because the IRS will impute interest on deferred payments if none is stated, or if the stated rate is below the applicable federal rate (AFR), the fix is straightforward: build an adequate interest rate into the earnout agreement from the start. Doing so at signing, at or above the AFR, avoids the imputed interest issue entirely rather than leaving it to be resolved unfavorably later.
Common Mistakes to Avoid
- Signing an earnout tied to personal performance without separating it from the business sale itself
- Assuming all earnout payments will be taxed as capital gain without confirming the structure supports that outcome
- Failing to address imputed interest in the agreement, leaving the IRS to impute it by default
- Not modeling the after-tax value of the earnout under different characterization scenarios before agreeing to terms
- Missing the installment sale election deadline, or not evaluating whether electing out of installment treatment is actually the better choice
- Overlooking state tax treatment of earnout payments, which varies significantly and isn't always aligned with the federal rules
The Bottom Line
Earnouts carry embedded tax complexity that isn’t visible on the surface of the deal terms. The structure of the agreement, not just the headline purchase price, determines whether a seller actually receives the after-tax economics they believe they negotiated, or a materially lower outcome once the IRS’s characterization and timing rules are applied. The moment to solve this is during negotiation and drafting, before the purchase agreement is signed, not when the first earnout payment lands and the tax return is due.
FAQ
- Q1: Are earnout payments taxed as capital gains or ordinary income?
A: It depends on what the payment is economically tied to. If the payment represents additional consideration for the business itself, it generally receives the same capital gain treatment as the rest of the sale (assuming the underlying asset was a capital asset held more than a year). If the payment is functionally compensation, tied to the seller's continued employment or personal performance, it's taxed as ordinary income instead. The label in the agreement matters less than the underlying economic substance.
- Q2: What is the installment method and does it apply to earnouts?
A: The installment method, under Section 453, allows a seller to recognize gain as payments are received rather than all in the year of sale. Most earnouts qualify, but because the total price is contingent rather than fixed, the seller must apply one of the IRS's contingent payment rules to determine how much gain to report each year, rather than using the straightforward fixed-price installment calculation.
- Q3: What is imputed interest and how does it affect my earnout payments?
A: When payments are deferred to future years, the tax code requires that part of each payment be treated as interest income, even if the agreement never states an interest rate. This imputed interest, under Section 483 or the OID rules, is always ordinary income, regardless of how the underlying sale gain is characterized. Stating an adequate interest rate (at or above the applicable federal rate) in the agreement at signing avoids having the IRS impute it later.
- Q4: How do I structure an earnout to avoid recharacterization as compensation?
A: The key is separating the earnout from any post-close employment arrangement. The purchase agreement should clearly establish the earnout as additional sale consideration, and any services the seller performs after closing should be documented and compensated separately, at market rates, under its own employment or consulting agreement.
- Q5: What happens if the earnout is tied to my personal performance post-close?
A: Earnouts tied to a seller's individual performance, such as personally retaining clients or personally hitting sales numbers, are at higher risk of being recharacterized as compensation rather than purchase price, and may also implicate personal goodwill, which has its own separate tax treatment. Tying milestones to overall business performance rather than the seller's individual actions reduces this risk.
- Q6: Can earnout payments be spread across multiple tax years?
A: Yes, that's typically the point of using the installment method. Gain is recognized in the years payments are actually received, which can help manage the seller's marginal tax rate across years rather than concentrating all the gain in the year of closing. The tradeoff is the added complexity of the contingent payment computation rules.
- Q7: What is open transaction treatment and when does it apply?
A: Open transaction treatment defers all gain recognition until the seller has recovered their entire basis in the business, and it's reserved for the rare cases where an earnout's value is genuinely too speculative to estimate. The IRS applies a high level of scrutiny to these claims, so sellers shouldn't plan around this treatment unless the facts clearly support it.
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