A CMBS loan, short for commercial mortgage-backed security loan, is a fixed-rate commercial real estate mortgage that the lender packages with other similar loans, transfers into a trust, and finances by selling bonds to investors. The borrower gets non-recourse financing on an income-producing property at relatively high leverage, and the lender clears the debt off its balance sheet by passing the credit risk through to bondholders. That securitized structure is what makes CMBS financing behave so differently from a loan you would get from a bank, and it drives almost every quirk a borrower runs into during the life of the loan.
How the Loan Becomes a Bond
A CMBS loan starts life like any commercial mortgage. A lender originates the loan against an income-producing property, but instead of holding it, the originator sells it along with dozens of other commercial mortgages to a financial sponsor or depositor. The depositor transfers the pool into a special-purpose legal entity, almost always structured as a Real Estate Mortgage Investment Conduit, or REMIC. That trust is the vehicle that issues bonds to investors.
The REMIC structure exists for a tax reason. Under the Internal Revenue Code, a qualified REMIC is not subject to entity-level federal income tax, so income flows directly to bondholders, who pay tax on their own share. Without that pass-through treatment, the whole structure would be uneconomical.
The bonds are divided into classes called tranches, stacked by seniority. Senior tranches, typically rated AAA, collect principal and interest first and carry the lowest risk. Subordinate tranches, sometimes called the “B-piece,” absorb losses first if underlying loans default. That waterfall lets investors pick their risk-reward profile and spreads credit risk across a wide pool of capital-market participants rather than leaving it on the originator’s books.
Most CMBS deals are conduit deals: pools of 30 to 80 loans from different borrowers, property types, and markets, with individual loans typically running from a few million dollars up to around $50 million. Diversification is the point. A separate category, the single-asset, single-borrower deal or SASB, is backed by one large loan on a single trophy property or portfolio, often exceeding $100 million, and offers no diversification benefit at all.
Loan Terms and Rates
CMBS loans carry fixed interest rates and typically come with terms of five, seven, or ten years. The monthly payment is calculated on a 25- to 30-year amortization schedule, so at maturity the borrower makes a balloon payment for the remaining principal. Some loans include an interest-only period during the early years, which preserves cash flow but leaves more principal outstanding at the balloon date.
Rates are priced as a spread over the swap rate, which roughly tracks U.S. Treasury yields. As of early 2026, conduit CMBS rates for stabilized properties generally run in the range of roughly 5.8% to 7.8%, though the exact rate depends on property type, leverage, and market conditions. The rate locks at closing and stays fixed for the full term, which is a large part of the appeal for borrowers who want predictable debt service.
Non-Recourse Protection and the Carve-Outs That Break It
CMBS loans are non-recourse. If the borrower defaults, the lender’s remedy is the property itself, and personal assets or other business holdings are generally shielded from a deficiency judgment. For borrowers with meaningful net worth or a portfolio of properties, isolating downside risk to a single asset is the headline reason to choose CMBS.
The protection has limits. Every CMBS loan includes “bad boy” carve-outs that let the lender pursue the borrower or a guarantor personally when certain triggering events occur. Some carve-outs create liability only for the actual losses the borrower’s actions caused. Others convert the entire loan to full recourse, no matter how small the damage. Common full-recourse triggers include a voluntary bankruptcy filing by the borrower entity and unauthorized transfers of ownership interests in the property. Other carve-outs that can create personal liability include allowing a senior lien to attach, committing waste, failing to keep the borrower entity as a separate legal entity with its own books and accounts, and violating the lockbox or cash management provisions of the loan documents. How broadly the loan defines “transfer” and “waste” matters a great deal, and these provisions are heavily negotiated.
Getting Out of the Loan Early
This is where CMBS diverges most sharply from bank financing. The bonds sold to investors promise a specific stream of payments over a set period, so the loan documents impose strict prepayment restrictions to protect that yield.
Every CMBS loan begins with a hard lockout, during which prepayment is flatly prohibited. Federal REMIC rules prevent defeasance until at least two years after the securitization closes, so borrowers face an absolute lockout for a minimum of that long regardless of what the loan documents say. Many loans extend the lockout beyond the statutory minimum.
After lockout expires, two mechanisms let a borrower exit:
- Defeasance. The borrower buys a portfolio of U.S. Treasury securities whose payment stream matches the remaining principal and interest due under the loan. The Treasuries replace the commercial property as collateral, the mortgage lien is released, and the trust keeps collecting its expected cash flow. The borrower hires a defeasance consultant and pays legal, accounting, and securities costs that can run into tens of thousands of dollars, on top of the cost of the Treasury portfolio itself.
- Yield maintenance. Rather than substituting collateral, the borrower pays a lump-sum prepayment penalty designed to make the lender whole. It is calculated as the present value of remaining scheduled loan payments, discounted at the current Treasury yield closest to the loan’s maturity date. When rates have fallen since origination, the penalty can be substantial, because the lender is losing an above-market rate. When rates have risen, the penalty shrinks and can occasionally approach zero.
Most loan documents drop prepayment restrictions 60 to 120 days before the maturity date, giving the borrower a narrow open window to refinance or pay off at par. That window is the only clean exit.
Loan Assumability
Assumability offsets some of the prepayment pain. When the borrower sells the property, the buyer can take over the existing CMBS loan instead of paying it off and originating new debt. This is especially valuable when the loan carries a below-market rate, because the new owner inherits that rate.
Assumption is not automatic. The buyer applies to the master servicer and must meet the same underwriting standards the original borrower did, including credit, net worth, and liquidity requirements. Assuming borrowers generally need a net worth of at least 25% of the loan amount and liquidity of 5% to 10%. The servicer charges an assumption fee, typically around 1% of the outstanding balance. That is meaningfully cheaper than defeasance or yield maintenance, which is why many CMBS property sales are structured as assumptions rather than payoffs.
What Properties Qualify and How Loans Get Sized
CMBS lenders focus almost entirely on the property’s income, not the borrower’s overall financial picture. The property has to be stabilized with predictable cash flow from existing tenants. Multifamily apartments, anchored retail centers, industrial warehouses, and well-leased office buildings are the core of conduit CMBS. Transitional properties, ground-up construction, and assets in the middle of major renovations do not fit, because the cash flow is too uncertain to support a securitized bond.
Three metrics drive loan sizing:
- Debt Service Coverage Ratio (DSCR). Net operating income divided by annual loan payments. Minimum DSCR requirements typically range from 1.25x to 1.50x depending on property type.
- Loan-to-Value (LTV). The loan amount as a percentage of appraised value. Most CMBS lenders cap LTV at 75%, and conservative programs top out at 65% for riskier property types.
- Debt yield. Net operating income divided by the total loan amount. This strips out the interest rate and amortization and tells the lender what cash return the property produces on the debt. In 2026, CMBS lenders generally require a minimum debt yield of 10% to 12%.
Underwriting is strictly asset-isolated. Whichever metric produces the smallest loan wins. A property might have strong DSCR but weak debt yield, and the debt yield decides the loan amount regardless of how the other numbers look.
Reserves and Escrows
CMBS lenders require reserve accounts funded at closing with ongoing monthly contributions. Expect escrows for property taxes and insurance, paid by the servicer from the reserve. The lender also requires a replacement reserve funded monthly based on the property condition assessment, covering items like roof replacements, HVAC systems, and parking lot resurfacing.
Office and retail loans often carry additional reserves for tenant improvements and leasing commissions, since those properties see periodic lease turnover that demands capital. If the property condition report flags needed repairs, the lender holds back an upfront repair reserve that gets released as the work is completed. Reserves tie up real capital, so factor them into the total cost of the loan rather than looking at the interest rate alone.
Who You Deal With After Closing
Once the loan enters the trust, the borrower never deals with the original lender again. A layered servicing structure takes over.
The Master Servicer
The master servicer handles day-to-day administration of every performing loan in the pool: collecting payments, managing escrow and reserve accounts, and remitting funds to the trust for distribution to bondholders. It earns a small fee based on outstanding principal and operates under the Pooling and Servicing Agreement, the governing contract for the entire securitization. Requests for lease consents or minor property modifications go through the master servicer.
The Special Servicer
When a loan stops performing, whether through a missed payment or a significant covenant violation, it transfers to the special servicer. The special servicer’s job is to maximize recovery for the trust. The PSA’s servicing standard requires it to act in the collective interests of all bondholders, not just the B-piece investors who typically hold the right to appoint or replace the special servicer. That creates an inherent tension, because the B-piece investors absorb losses first and their power to replace the special servicer can influence how aggressively workouts are pursued.
The special servicer has broad discretion to modify the loan, negotiate a discounted payoff, take the property through foreclosure, or sell the note at a discount. This is where the absence of relationship lending really bites. Unlike a bank that might grant forbearance to a longstanding client, the special servicer has no prior relationship with the borrower and evaluates the situation purely on the numbers. Recovery of principal is the only objective.
Advantages and Trade-Offs
CMBS financing fills a specific niche, and being clear about the trade-off matters more than the pitch.
Where CMBS Loans Work Well
Non-recourse structure is the headline. Borrowers with significant personal wealth or multiple properties can isolate downside risk to one asset. CMBS lenders offer relatively high leverage compared to portfolio lenders, often going to 75% LTV for strong assets. The fixed rate eliminates rate risk for the full term, and pricing is often competitive with or better than what a commercial bank would offer a comparable borrower. Cash-out refinancing is available. Assumability gives a seller a genuine exit that avoids prepayment penalties entirely.
Where They Fall Short
Flexibility is the fundamental cost. Once the loan is securitized, the borrower’s lender is effectively a trust governed by a 400-page contract. Requesting consent, modifying a lease requirement, or approving a capital expenditure means dealing with a servicer that has no discretion to deviate from the PSA. Prepayment through defeasance or yield maintenance is expensive and slow. If the property hits financial trouble, there is essentially no path to informal forbearance. The loan transfers to special servicing, and the borrower negotiates from a position of weakness with a party focused exclusively on bondholder recovery. Anyone used to the give-and-take of a bank relationship should go in expecting a very different experience.