Most acquisitions in the lower-middle market get done with a senior loan and some equity. That combination works until it does not. When the purchase price stretches beyond what a bank will finance and the buyer does not want to dilute equity further, mezzanine debt enters the stack.
Understanding how it works matters whether you are buying a business or selling one.
What mezzanine debt is
Mezzanine debt sits between senior secured debt and equity in a company's capital structure. In a standard LMM buyout, the stack looks like this:
- Senior debt: lowest risk, first claim in liquidation, lowest cost (typically 7-9% in current markets)
- Mezzanine debt: subordinated, second claim, higher cost (12-20% all-in, often split between cash interest and payment-in-kind)
- Equity: highest risk, residual claim, unlimited upside
Mezzanine lenders accept a subordinated position in exchange for a higher return. That return comes through a combination of interest rate, fees, and often an equity kicker: warrants or the right to purchase a small percentage of the company at a fixed price. According to Bain's Global Private Equity Report, mezzanine remains a standard component in buyout capital structures where senior leverage alone cannot cover the purchase price.
Where mezz fits in LMM deals
In deals under $50M enterprise value, mezzanine debt typically covers 10-20% of total capital. A $20M acquisition might look like this:
- $12M senior bank debt (60%)
- $4M mezzanine debt (20%)
- $4M equity (20%)
The mezzanine tranche lets the buyer close a deal that would otherwise require more equity, which dilutes LP returns, or a seller note structure at full subordination, which sellers often resist.
For businesses with $2M to $10M in EBITDA, senior lenders typically advance 3-4x EBITDA. If the purchase price is 7-8x, there is a gap. Mezzanine fills it.
The real cost of mezz capital
Mezzanine is expensive. That is the honest framing.
Cash interest runs 10-14% on the subordinated balance. Add payment-in-kind (PIK) interest, where unpaid interest accrues to the principal rather than being paid in cash, and the effective rate climbs to 15-18%. Origination fees add another 1-2 points upfront.
The equity kicker is where lenders recoup the difference versus senior debt yields. Warrants for 2-5% of the company, exercisable at a low price, create meaningful upside if the business performs. A mezzanine lender who places $4M at 15% all-in and holds warrants for 3% of a $20M company has a fundamentally different return profile than a bank at 8%.
What this means practically: in a deal where senior debt costs $12M at 8.5% and mezz costs $4M at 16%, the blended cost of debt is about 10%. The business must generate enough operating cash flow to service both tranches before equity sees any distributions.
Covenants and control provisions
Mezzanine agreements carry more restrictions than senior debt but fewer than equity investors typically demand. Common provisions include:
- Minimum EBITDA or coverage ratio tests (measured quarterly)
- Limits on additional debt incurrence
- Change-of-control protections
- Board observer rights (not voting seats in most LMM deals)
- Mandatory prepayment on asset sales above a threshold
Call protection is standard. Most mezz instruments carry a no-call period of 18-24 months, then a declining premium (2-1-0%). Prepaying mezzanine debt early costs money.
What sellers need to know
If you are selling and the buyer is using mezzanine debt, a few things follow directly.
First, the buyer's equity is smaller relative to deal size. That is not inherently bad, but it means the business must perform to service debt. Operators who stay involved post-sale through earnout, consulting, or rollover equity should understand the cash flow obligations sitting above any distributions.
Second, mezzanine lenders move faster than banks for diligence and approval, but their term sheets carry more negotiating points. Close timelines can extend if mezzanine lenders require financial model reviews or management presentations.
Third, a seller note behind senior debt is already subordinated to banks. A seller note behind both senior debt and mezzanine is deeply subordinated. Sellers who want to carry a note should understand where it sits in the stack before accepting a term sheet. See our guide to letter of intent mechanics in business acquisitions for how these structures get documented at the offer stage.
Mezzanine vs. seller financing
Many LMM buyers propose a seller note as an alternative to mezz. The economics look similar: subordinated debt, 5-8 year term, 6-8% interest. The practical differences matter.
A seller note is patient capital. Most sellers do not enforce covenants with the discipline a mezzanine lender will. That flexibility has value for the buyer and corresponding risk for the seller.
A mezzanine lender is not patient. They have their own LPs expecting returns. They will enforce. That enforceability adds discipline to the capital structure that some operators actually want: it creates accountability to a financial partner with real monitoring infrastructure.
When mezz makes sense and when it does not
Use mezzanine debt when:
- The acquisition requires more leverage than senior lenders will advance
- The buyer wants to minimize equity dilution to LPs or co-investors
- The business has stable, predictable cash flow that can service high-cost debt
- The timeline matters and the buyer needs to close without a prolonged bank process
Avoid mezzanine debt when:
- The business cash flow is seasonal or uncertain (PIK accrual in down periods compounds fast)
- The purchase price already stretches valuation
- The operator has never managed a leveraged capital structure
The operator's view
At Patriot Growth Capital, we focus on businesses with $2M to $10M in EBITDA where the owner is ready to transition. Many of these deals involve some form of subordinated financing. The structure itself is not the strategy. Operations are.
Mezzanine debt does not fix a business with declining revenue or margin compression. It amplifies whatever trajectory is already in place. Put mezz capital behind a business with strong fundamentals, a clear growth path, and an operator who has been through the diligence process, and it is a tool worth using. Put it behind a broken operating model and you have expensive debt on a declining asset.
Operators who know what they owe, to whom, under what conditions, and what triggers default are operators who can run a business through difficulty. Capital structure literacy is part of what we develop across the 60-month operator pipeline.
Frequently Asked Questions
What is mezzanine debt in a private equity deal?
Mezzanine debt is subordinated financing that sits between senior bank debt and equity in an acquisition capital structure. It carries higher interest rates than senior debt, typically 12-20% all-in, because it takes a junior position in repayment priority. Lenders often receive equity warrants as additional compensation for the added risk.
How does mezzanine debt affect a business owner selling their company?
If a buyer uses mezzanine debt, the business must generate enough cash flow to service multiple layers of debt before distributions flow to equity holders. Sellers who negotiate earnouts or rollover equity should understand where their interest sits in the repayment waterfall relative to mezz and senior debt obligations.
What is the typical size of a mezzanine tranche in a lower-middle-market buyout?
In deals under $50M enterprise value, mezzanine debt typically represents 10-20% of total capital. On a $20M acquisition, that means a $2M to $4M subordinated tranche filling the gap between what senior lenders will advance and the equity the buyer is willing to contribute.
How is mezzanine debt different from a seller note?
Both are subordinated to senior bank debt, but the key difference is enforcement. A mezzanine lender is a professional capital provider with active covenants, monitoring requirements, and accountability to its own investors. A seller note is typically more patient with fewer covenant requirements, which creates flexibility for the buyer but more risk for the seller.
