Buy-Sell Agreement Guide: Structure, Tax, and Funding for Business Owners

If you own a business with partners, your buy-sell agreement is your exit plan — whether you use it or not. Most owners sign whatever the attorney hands them at formation and never think about it again. Then a trigger event hits, and the structure they chose ten years ago produces a tax bill or a buyout price that makes no sense. Here's how to get it right.

What a buy-sell agreement does (and why every multi-owner business needs one)

A buy-sell agreement — also called a business continuation agreement or shareholder agreement — is a legally binding contract between co-owners that governs what happens to an owner's interest when they exit. It answers the questions that become very expensive to answer in court:

• What triggers a forced buyout?
• How is the business valued at that moment?
• Who buys the departing owner's interest?
• How and when does the buyer pay?
• What are the tax consequences?

Without an agreement, a partner's death puts their business interest into their estate, meaning their spouse or heirs may become your new co-owner — with equal voting rights, profit distributions, and the ability to force a dissolution. A buyout triggered by a disability or divorce without an agreement produces years of litigation and a business-damaging distraction at exactly the wrong moment.

For sole owners anticipating a sale to a third party, a buy-sell agreement isn't relevant in the same way. But for any business with two or more equity owners — LLCs, S-corps, C-corps, or partnerships — it's as essential as the operating agreement itself.

Triggering events

A well-drafted buy-sell agreement specifies exactly what events activate the buyout obligation. Standard triggering events include:

• Death. The most commonly funded trigger. Death benefit proceeds from life insurance fund the buyout at close.
• Disability. Typically defined as inability to work in the same capacity for 12 or 24 consecutive months. More difficult to fund and often underfunded or excluded.
• Retirement. Voluntary exit at a specified age or after a specified tenure.
• Voluntary exit (non-retirement). An owner who wants to sell their interest before retirement age. Often includes a right of first refusal for the remaining owners before going to a third party.
• Divorce. Protects the remaining owners from an ex-spouse becoming a co-owner. Typically requires the owner to buy out the business interest from their ex-spouse using the buy-sell valuation, then retain full ownership interest inside the business.
• Bankruptcy or insolvency. Prevents a creditor or trustee from acquiring an ownership interest.
• Deadlock or irreconcilable disagreement. "Shotgun" clauses or buy-sell triggers for 50/50 partnerships where no decision can be made.

Review each triggering event carefully. Omitting disability is a common mistake in older agreements — disability is statistically more likely than death for working-age owners, yet many agreements only fund the death trigger.

The core structural choice: redemption vs. cross-purchase

Once a trigger fires, the buyout can be structured in one of two ways. This is the most consequential decision in a buy-sell agreement, and it's often made at formation without appreciating the tax difference.

Redemption agreement (entity purchase)

The business itself buys back the departing owner's interest. For corporations, this is a stock redemption under IRC § 302. For LLCs and partnerships, it's a liquidating distribution under IRC § 736.

In a redemption, the remaining owners don't buy anything directly — their ownership percentage increases automatically as the departing owner's shares are retired. But they get no basis step-up in the business's underlying assets or in the surviving shares. Their cost basis in their existing shares remains unchanged, even though each share now represents a larger slice of the company.

Example: Three equal owners of a $12M S-corp. One dies. The corporation redeems the deceased's $4M interest. The two surviving owners each go from 33% to 50% — but their basis in each share doesn't change. When they eventually sell, their gain calculation uses the original basis, not $4M each.

Cross-purchase agreement

The remaining owners personally buy the departing owner's interest. Each surviving owner purchases a proportionate share of the departing owner's equity directly from them (or their estate).

The key advantage: each buying owner gets a stepped-up basis in the newly acquired shares equal to what they paid. In a sale years later, that higher basis directly reduces their taxable gain.

Using the same $12M S-corp example: if each surviving owner pays $2M for half of the deceased owner's interest, their basis in those shares is $2M — not whatever their original shares cost. When they eventually sell, they're taxed only on appreciation above $2M for those shares.

Which structure is better?

It depends on your situation, but here's the general framework:

• Cross-purchase favors remaining owners when the business has substantial unrealized appreciation — the step-up in basis translates directly to lower future capital gains tax.
• Redemption is simpler with many owners (cross-purchase requires N×(N-1) life insurance policies — 3 owners = 6 policies, 4 owners = 12 policies). Redemption uses one policy per owner owned by the entity.
• C-corps with QSBS eligibility: the departing shareholder's ability to exclude gain under § 1202 is determined by their own holding period and acquisition method — not by whether the buyout is structured as a redemption or cross-purchase. But the remaining owners who buy in a cross-purchase are acquiring stock in the secondary market, not at original issuance, so they cannot use § 1202 on those acquired shares. Future QSBS planning for remaining owners requires separately issued shares at original issuance.
• S-corps should review debt basis implications. If the company has significant debt, a redemption changes the debt basis picture for remaining owners. This needs modeling before choosing structure.

Valuation: the method matters as much as the number

The buy-sell agreement must specify how the business will be valued when a trigger fires. There are three main approaches, and the choice has enormous practical consequences.

Fixed price

Owners agree on a specific dollar value at formation, then update it annually (or fail to). In practice, most owners set the price at formation and never revisit it — until a trigger fires and the fixed price is 20% of the actual fair market value. Fixed price works only if owners have the discipline to update it annually in writing. They almost never do.

Formula-based valuation

The agreement specifies a formula — typically a multiple of EBITDA, revenues, or book value. Example: "6× trailing 12-month EBITDA." This avoids the stale-price problem but creates a new one: the formula must be appropriate for how the business actually trades. A 6× EBITDA multiple might be reasonable today but off by 2–3× in either direction depending on market conditions, deal size, and buyer type at the time of trigger. The formula also creates incentive problems — owners nearing retirement may manage earnings to maximize the formula-derived buyout price.

Appraisal (fair market value)

The agreement requires an independent business appraisal at the trigger date. Most lawyers prefer this because it reflects reality. But it introduces delay (appraisals take 30–90 days), dispute risk (departing and remaining owners often commission conflicting appraisals), and cost. Better-drafted agreements use a single agreed-upon appraiser or a panel process with a third appraiser as tiebreaker.

Funding the buyout: life insurance, disability insurance, and installment notes

Knowing the buyout price is one thing. Having the cash to pay it on the day a trigger fires is another. Most agreements are underfunded. Here are the realistic options.

Life insurance (death trigger)

Life insurance is the cleanest funding mechanism for the death trigger. The death benefit pays out immediately, is generally income-tax-free under IRC § 101(a), and the proceeds can fund the entire buyout at close.²

The key design issues:

• Term vs. permanent. Term insurance expires. If an owner is still in the business at 65 when a 20-year term policy expires, you've lost the funding mechanism. Permanent policies (universal life, whole life) are more expensive but don't lapse if premiums are paid.
• Coverage amount. The policy face value should match or exceed the agreed-upon buyout price. As the business grows, the coverage should be reviewed and increased if the formula or appraisal would produce a number above the current death benefit.
• Who owns the policy? This is where redemption vs. cross-purchase creates a practical difference.

In a redemption agreement

The corporation owns and is the beneficiary of a policy on each owner's life. Administratively simple — one policy per owner. When a trigger fires, the corporation collects the death benefit and uses it to fund the share redemption.

Important: If the corporation owns life insurance on employees (including owner-employees), IRC § 101(j) requires written notice to and consent from the insured, plus annual information reporting on Form 8925.³ Failure to comply means the death benefit above the insurer's basis is taxable — a very expensive mistake at exactly the wrong moment. Most businesses comply by having owners sign consent forms at policy issuance, but this needs to be documented and maintained.

In a cross-purchase agreement

Each owner personally owns and pays premiums on policies covering the other owners' lives. With 2 owners: 2 policies (A owns policy on B; B owns policy on A). Simple. With 3 owners: 6 policies. With 4 owners: 12 policies. With 5 owners: 20 policies.

The administrative burden of individual cross-purchase policies grows quickly. The common workaround is an LLC trustee arrangement: a purpose-built LLC owns all the policies, collects death benefits, and distributes proceeds to the surviving owners to fund the cross-purchase. This preserves cross-purchase basis step-up benefits while keeping policy administration manageable.

Premiums paid by individual owners (or the LLC trustee) are not deductible — they're paid with after-tax dollars. Life insurance premium deductibility ended with TCJA for C-corps in most cases and was never available for key-person or buy-sell life insurance in pass-through entities.

Disability buyout insurance

Disability is significantly more likely than death for working-age owners, yet most buy-sell agreements either omit disability buyout funding entirely or assume the business will fund it from operating cash. Neither is reliable.

Disability buyout insurance pays a lump sum or installment benefit when an owner meets the policy's definition of total disability, typically after a 12–24 month waiting period (the "elimination period"). The insurer then funds some or all of the buyout over a period matching the agreement's payment terms.

Coverage is typically available up to 70–80% of the buyout price, with maximum benefit limits that decline as the insurable value rises. For high-value businesses ($20M+), the disability buyout market becomes thin and policies expensive — an installment note from the departing owner is often the de facto disability funding mechanism.

The disability trigger definition in your agreement should match the policy definition exactly. A mismatch between when the agreement requires a buyout and when the policy pays creates a coverage gap that falls on the remaining owners personally.

Installment note (seller financing)

When insurance is unavailable, insufficient, or the trigger is retirement or voluntary exit, the departing owner takes a promissory note from the buyer (entity or co-owners) in lieu of immediate cash. The note must charge at least the Applicable Federal Rate (AFR) to avoid IRS imputed-interest issues under IRC § 1274.⁴

Current AFR floors (May 2026, Rev. Rul. 2026-09):

• Short-term (≤3 years): 3.89% annual
• Mid-term (3–9 years): 4.08% annual
• Long-term (>9 years): 4.50% annual

From the departing owner's perspective, an installment note buyout creates installment sale treatment under IRC § 453 — they recognize gain only as payments are received, which can significantly reduce peak-year tax liability. See our Installment Sale Strategy Guide for the full mechanics.

From the remaining owners' perspective, the installment note is a liability the business or they personally must service. This should be modeled carefully: can the business or buyers service the note from operating cash flow without impairing operations?

Tax treatment at trigger: redemption vs. cross-purchase in detail

C-corps and S-corps: IRC § 302

For corporate entities, the tax treatment of a redemption depends on whether it qualifies as a "sale or exchange" rather than a dividend under IRC § 302.⁵ A redemption qualifies for capital gain treatment if:

• Complete termination of interest: The departing shareholder's entire interest is redeemed (including constructive ownership via family attribution). This is the cleanest path — applies in most buy-sell buyout scenarios.
• Substantially disproportionate: The departing shareholder's ownership falls below 50% and to less than 80% of their pre-redemption percentage. Used for partial redemptions.
• Not essentially equivalent to a dividend: A residual category for cases that don't meet the above mechanical tests but are clearly redemptions, not disguised dividends.

If a redemption doesn't qualify under § 302, the entire amount is treated as a dividend — ordinary income, no capital gain rates. This is a significant distinction in a redemption of a departing owner's full interest in a closely held C-corp. The § 302(b)(3) complete-termination rule normally applies cleanly, but family attribution issues can prevent qualification if the departing owner has family members remaining in the company. A tax advisor should review any redemption where family members retain interests.

Partnerships and LLCs: IRC § 736

Partnership buyouts follow IRC § 736, which bifurcates the buyout payment into two categories:⁶

• § 736(b) payments — for the departing partner's share of partnership property (assets, capital). These are capital gain to the departing partner (with possible § 1231 recapture on depreciated assets).
• § 736(a) payments — for unrealized receivables and, importantly, goodwill unless the partnership agreement specifies otherwise. These are ordinary income to the departing partner and a deductible payment to the partnership.

The goodwill treatment under § 736(a) vs. § 736(b) is a planning lever: if the partnership agreement specifies that the departing partner will be paid for goodwill under § 736(b), the payment is capital gain. Without that language, goodwill goes to § 736(a) — ordinary income. Many partnerships leave this on the table by accident.

Common mistakes in buy-sell agreements

1. Fixed price that was never updated

The most common problem: owners set a value at formation and forget to update annually. A $3M fixed price on a business that's now worth $12M creates an obligated windfall for the buyers and a catastrophic outcome for the departing owner's family.

2. Underfunded or unfunded disability trigger

The disability trigger exists in the agreement but has no insurance behind it and no installment structure. When the trigger fires, the remaining owners either can't afford the buyout or negotiate under distress — rarely a good outcome for either side.

3. Wrong structure for the entity type

A cross-purchase agreement in an S-corp with 6 owners means 30 life insurance policies and complex administration. A redemption agreement in a C-corp with significant unrealized appreciation and no QSBS eligibility permanently loses the step-up benefit for remaining owners. The structure chosen at formation should match the ownership structure and tax situation as it is today, not as it was at formation.

4. § 101(j) non-compliance for corporate-owned policies

Corporate-owned life insurance on employee-owners requires IRC § 101(j) notice and consent documentation and annual Form 8925 filing. Missing this means the death benefit above the insurer's basis is taxable income — often discovered at exactly the moment the death benefit is needed.

5. Valuation method that conflicts with § 2703

A formula or fixed price that significantly undervalues the business may be disregarded by the IRS for estate tax purposes. The estate pays tax based on actual FMV, but the family only receives the formula price under the agreement. The § 2703 safe harbor requires the agreement to represent a bona fide business arrangement at arm's-length terms — which means the formula price should approximate what would be negotiated between unrelated parties.

6. No right of first refusal for third-party sales

An owner decides to sell their interest to an outside buyer. Without a ROFR provision, the remaining owners must accept this new co-owner. A well-drafted agreement gives remaining owners (or the entity) the right to match any third-party offer before the owner can sell outside.

When to review and update your buy-sell agreement

A buy-sell agreement written at formation is written for the company as it was then, not as it is today. Review triggers:

• Annually — confirm valuation is current; update fixed price if applicable; confirm insurance coverage keeps pace with business value.
• Major equity change — new owner added, owner exits, ownership percentages shift.
• Business value doubles — insurance face amounts and formula multipliers need recalibration.
• Entity conversion — C-corp to S-corp (or reverse) changes both § 302 analysis and QSBS eligibility; the buy-sell should be re-reviewed at conversion.
• Owner disability, divorce, or near retirement — the trigger events become imminent; confirm funding is in place.
• Major tax law changes — TCJA, OBBBA, and SECURE 2.0 each changed the planning landscape. An agreement drafted in 2017 may use stale assumptions.