What is the actual difference between second lien and mezzanine?
The mechanism that puts each one behind the senior lender. A second lien loan is secured on the same collateral as the first lien facility, and it stands second because its lien ranks second, under an intercreditor agreement that says so. Mezzanine debt is typically unsecured, and it stands behind the senior facility because a subordination agreement says its claims are junior by contract. Same queue position, reached by different law.
Everything else that distinguishes the instruments follows from that mechanism. A second lien lender's downside analysis runs on collateral value: what the assets fetch, and what is left after the first lien is satisfied. A mezzanine lender's runs on enterprise value and the stream: it expects nothing from the collateral and prices accordingly, taking a higher coupon, often part in payment-in-kind, and usually a warrant that pays only if the equity does well.
The practical consequence for a borrower is that the two tranches behave differently in every phase. Second lien reads like tighter, cheaper, secured money with a lender whose behaviour in a stress is governed by the intercreditor terms. Mezzanine reads like more expensive, more flexible, equity-adjacent money whose provider diligences the business the way a minority investor would.
What does each one cost right now?
Second lien term debt prices at S+725 to 825 for borrowers with $15m to $40m of EBITDA, and subordinated debt for the same band at an all-in 11.0% to 13.5% (Lincoln International, Private Credit Snapshot, as of 1 May 2026). Below $10m of EBITDA the junior layer rarely splits into instruments at all: junior capital and mezzanine, counting cash and payment-in-kind interest together, runs 13.00% to 16.00% (SPP Capital Partners, Market At A Glance, July 2026).
The quoted costs are not directly comparable, which is the trap in every grid. The second lien spread converts to an all-in rate at the prevailing base rate, a one-month Term SOFR of 3.65% on the reference date (CME, 4 August 2026), and that is close to the whole of its cost. The mezzanine coupon is the visible part of a package that also carries the payment-in-kind accrual, which compounds to maturity, and the warrant, which costs nothing unless the business succeeds and then costs real money.
Deferral is standard enough to measure: payment-in-kind interest was being taken on 10.6% of direct lending loans as at 31 March 2026, the highest share since late 2020 (Lincoln International, published 7 May 2026). A mezzanine structure that defers part of its coupon by design is a normal structure. The same deferral arriving mid-life, because the cash portion could not be paid, is a signal, and every lender in the stack reads it as one.
| Feature | Second lien | Mezzanine and subordinated |
|---|---|---|
| Ranking mechanism | Second-ranking lien on collateral | Contractual subordination, usually unsecured |
| Pricing, $15m to $40m EBITDA band | S+725 to 825 | 11.0% to 13.5% all-in |
| Coupon form | Cash pay | Cash plus payment-in-kind accrual |
| Equity component | None typical | Warrant customary |
| Governing side agreement | Intercreditor agreement | Subordination agreement |
| Downside posture | Enforce against collateral, second | Negotiate; payment blockage risk |
What happens to each in a downside?
The second lien lender goes to the collateral, second. Its recovery is whatever the assets realize beyond the first lien claim, and its conduct on the way there is scripted by the intercreditor agreement: how long its remedies are stood still while the senior lender acts, what payments to it can be blocked, and who controls an enforcement. Those terms vary more between deals than the pricing does, and two second lien facilities at identical spreads with different intercreditor terms are different instruments.
The mezzanine lender negotiates, because it usually has nothing else. With no lien to enforce, its leverage in a stress is contractual and commercial: consent rights, the threat of blocking a consensual deal, and the fact that a restructuring that wipes the junior tranche also ends the relationship the sponsor or owner may need again. Its subordination agreement will typically block payments to it while the senior facility is in default, which is why its documents are negotiated hardest around exactly that clause.
For the borrower, the downside behaviour is a real selection criterion, not a lawyers' detail. A stressed year with a second lien in the structure is a three-party negotiation governed by the intercreditor. The same year with mezzanine is usually a two-stage negotiation, senior first, junior after, in which the mezzanine holder's incentives sit closer to the equity's than either admits in good times.
Which structure fits which situation?
Second lien fits where the first lien is worth keeping and the senior documents leave room for it. A senior facility priced in a better market, with room in its permitted-debt and permitted-lien baskets, is an asset; layering a secured second lien behind it adds capacity while the existing facility runs. The borrower needs the cash flow to pay a full cash coupon, and a senior lender willing to share its collateral on negotiable intercreditor terms.
Mezzanine fits where cash needs protecting or the senior lender will not share. The payment-in-kind option preserves liquidity through a growth phase or an integration; the absence of a second lien keeps the senior lender's collateral position clean, which some banks simply require; and the warrant aligns a provider that is being asked to take something close to equity risk. It is the instrument for a defined gap with a defined exit, priced accordingly.
Size decides more of this than preference does. The whole junior layer below roughly $10m of EBITDA is about half a turn to three quarters of a turn wide (SPP Capital Partners, July 2026), which is one tranche's width: the real choice at that size is a unitranche or a single junior instrument, not a stacked structure. The second-lien-versus-mezzanine question becomes live in the core middle market, where the layer is wide enough to structure.
“Borrowers ask which junior tranche is cheaper. The better question is which one they can live with in a bad year, because that is the year the two instruments stop being interchangeable.”
What should a borrower negotiate in either?
In a second lien: the intercreditor agreement, ahead of the spread. Standstill length, payment blockage triggers and duration, the second lien lender's rights in an insolvency, and whether it can buy out the first lien position all determine how the structure behaves when it matters. All of it is negotiated at close, when it is cheap, and none of it can be fixed later at any price worth paying.
In mezzanine: the cash and payment-in-kind split, the warrant's size, strike and treatment on prepayment or sale, and the call protection. Each is a real cost that never appears in the quoted coupon, and each has more provider-to-provider dispersion than the rate does, which is the practical argument for running more than one provider even for a small tranche.
In both: the definitions. Junior tranches test and size off the same adjusted earnings definition the senior facility uses, or a worse one, and a definition conceded in the junior documents has a way of migrating into the senior amendment that follows. The layer may be small. The precedent is not.
As of September 2026
Sources: Lincoln International, Private Credit Snapshot, as of 1 May 2026, for second lien and subordinated debt pricing by EBITDA band; SPP Capital Partners, Market At A Glance, July 2026, for blended junior capital and mezzanine pricing below $10m of EBITDA and for the senior and total leverage bands that size the junior layer; Lincoln International, published 7 May 2026, as at 31 March 2026, for the share of direct lending loans carrying payment-in-kind interest; CME, 4 August 2026, for one-month Term SOFR. Structural and downside behaviour is described at the level of market convention; intercreditor and subordination terms vary by transaction and no specific document is described. No named source in our set prices warrant coverage as a current market series, and no figure is offered.
This position sits within our second lien practice.