Close a floating rate bridge or construction loan and one line item shows up in the sources and uses that many borrowers see for the first time at the term sheet stage: the interest rate cap premium. It is not optional. Nearly every floating rate lender in commercial real estate requires one, and the check is written upfront, at closing, before the first draw is funded.
Despite being a standard requirement, interest rate caps are one of the least understood pieces of floating rate financing. This post breaks down what an interest rate cap actually is, how it pays out, why lenders insist on them, how the strike gets set, and what caps cost in today’s market.
What an Interest Rate Cap Actually Is
An interest rate cap is a derivative contract that works like insurance against rising interest rates: the borrower pays an upfront premium, and if the floating index rises above an agreed ceiling, the cap provider pays the borrower the difference. In CRE, the index is almost always SOFR (Secured Overnight Financing Rate), which replaced LIBOR as the benchmark for floating rate loans.
Three terms define the contract. The notional is the dollar amount being hedged, typically the full loan balance. The strike is the ceiling rate on the index. The term is how long the protection runs, usually matched to the initial term of the loan. Under the hood, a cap is a series of monthly options (caplets), each covering one interest period. If SOFR resets above the strike in a given month, that month’s caplet pays. If it resets below, it expires worthless and the borrower simply pays its regular floating rate.
The key point for borrowers: the cap does not change the loan. The borrower still pays SOFR plus spread to the lender every month. The cap provider, a bank counterparty separate from the lender, reimburses the borrower for any interest attributable to SOFR above the strike.
How a Cap Pays Out: A Worked Example
Consider a $30 million bridge loan priced at SOFR + 275 with a 4.00% strike cap on the full notional. If SOFR spikes to 5.50%, the borrower’s coupon would float to 8.25%. But the cap provider owes the difference between SOFR and the strike: 5.50% − 4.00% = 1.50%, and $30,000,000 × 1.50% = $450,000 per year, or roughly $37,500 per month.
Net of the cap payments, the borrower’s effective rate can never exceed the strike plus the spread: 4.00% + 2.75% = 6.75% worst case, no matter how high SOFR runs. That certainty is exactly what the lender is buying when it makes the cap a condition of closing. It converts an open-ended interest rate exposure into a defined, underwritable maximum debt service.
Why Lenders Require Caps on Floating Rate Loans
Lenders underwrite floating rate loans to a simple question: can the property service the debt if rates move against it? On a stabilized asset with a fixed rate loan, debt service is known. On a floating rate bridge or construction loan, it is not, and the deals that take floating rate debt are precisely the ones with the least cushion: lease-up plays, renovations, and ground-up projects running off an interest reserve rather than in-place cash flow.
A cap solves three problems at once for the lender. First, it puts a hard ceiling on debt service, so DSCR and interest reserve sizing hold up in a rising rate scenario. (For how coverage tests drive loan sizing, see our other post on DSCR.) Second, it protects the interest reserve itself: without a cap, a rate spike can burn through a construction loan’s reserve months early and force a capital call the sponsor may not be able to meet. Third, for lenders who finance their books with warehouse lines or securitization, a rated cap is often a requirement passed down from their own capital sources. Agency and CLO executions in particular require caps from rated counterparties, with the cap collaterally assigned to the lender.
The 2022-2023 tightening cycle showed why. Borrowers who closed floating rate loans in 2021 with SOFR near zero watched the index climb more than 500 bps in under 2 years. The ones holding caps had a counterparty writing checks every month. The ones without became the distress pipeline.
How Lenders Set the Strike
The strike is not arbitrary. Lenders typically solve for the highest all-in rate at which the property still covers debt service at the required DSCR, and set the strike so the capped rate stays at or below that level.
Run the math on a $25 million interest-only bridge loan against a property producing $2,100,000 in NOI, with the lender requiring a 1.20x DSCR at the capped rate. Maximum annual debt service is $2,100,000 ÷ 1.20 = $1,750,000. On a $25 million balance, that implies a maximum all-in rate of $1,750,000 ÷ $25,000,000 = 7.00%. With a 300 bps spread, the strike lands at 7.00% − 3.00% = 4.00%.
The implication for borrowers: strike selection is a negotiation with real dollars attached. A lower strike costs more upfront but caps debt service tighter. A higher strike is cheaper but only clears underwriting if the deal’s cash flow supports it. Sponsors who model this before going to market avoid getting repriced at the term sheet stage.
What Drives the Premium
Cap pricing is option pricing, and 4 variables do the work:
- Strike relative to the forward curve. The closer the strike sits to where the market expects SOFR to go, the more likely the cap pays out, and the more it costs. Strikes well above the forward curve are cheap; at-the-money strikes are not.
- Term. A 3-year cap costs meaningfully more than a 2-year cap because it adds 12 more months of caplets, and the later months carry the most uncertainty.
- Implied volatility. When the market is confident about the rate path, caps are cheap. When it is not, as in 2022-2023, premiums explode.
- Notional. Cost scales with the balance being hedged, and lenders generally require the full loan amount to be covered.
What Caps Cost in Today’s Market
The good news for borrowers in mid-2026: this is the cheapest cap market since the Fed began tightening in 2022. SOFR sits at 3.63% as of July 14, 2026, per Federal Reserve Bank of New York data, with the Fed’s target range at 3.50% to 3.75% after a series of cuts that began in September 2024. The forward curve is roughly flat, with the market pricing about one more 25 bps cut by year-end. A flat-to-declining curve and subdued volatility both compress cap premiums.
Contrast that with the peak. In March 2023, Commercial Observer reported that a 2-year cap at a 4.00% strike on a $25 million loan cost roughly $569,000, up from $97,000 a year earlier. That is a jump from 0.39% of the loan amount to 2.28%, nearly 6x, for identical protection. Today, with spot SOFR at 3.63%, that same 4.00% strike sits above the index rather than far below it, and premiums have fallen accordingly.
Pricing moves daily with the curve, so treat any quote as perishable. Hedging advisors such as Chatham Financial and Pensford publish indicative pricing tools that let borrowers ballpark cost by notional, strike, and term before engaging a broker to run a live auction among cap providers. As a budgeting matter, sponsors should carry a cap line in the closing costs from the first model draft and refresh the quote at application, at rate lock, and again before closing.
Structuring Details That Catch Borrowers Off Guard
A few provisions in loan documents deserve attention before signing:
- Cap term vs. loan term. Lenders typically require the cap through the initial maturity only. Exercising an extension option usually triggers a replacement cap requirement, purchased at whatever the market charges then. Borrowers in 2023 learned this the hard way when 1-year replacement caps cost more than the original 3-year caps.
- Rating requirements. Loan documents specify minimum counterparty ratings. If the cap provider is downgraded, the borrower may be obligated to replace the cap mid-term.
- Collateral assignment. The cap is pledged to the lender, and payments typically route through the servicer or lender-controlled account rather than to the borrower directly.
- Springing caps. Some balance sheet lenders allow the borrower to defer buying the cap unless SOFR crosses a trigger. That saves upfront cost but guarantees the cap will be bought at the worst possible time if the trigger hits.
Why Cap Fluency Matters
An interest rate cap is a real cost and a real negotiation, not a checkbox. The strike drives both the premium and the loan sizing, the term structure creates replacement risk at extension, and the market price swings with every repricing of the Fed’s path. As a general rule: budget the cap from day one, push the strike as high as underwriting allows, and get live quotes before signing an application, not after. Walking into a floating rate deal with a clear view of what the cap costs, and why the lender is asking for it, is not only helpful, but expected.
References
- Federal Reserve Bank of New York, Secured Overnight Financing Rate data, July 2026.
- Board of Governors of the Federal Reserve System, FOMC statement and projections, June 2026.
- Commercial Observer, “Rising Interest Rate Cap Costs Pressure CRE Borrowers,” March 2023.
- Chatham Financial and Pensford, interest rate cap pricing resources and calculators.
