Study for the CCMB by linking each underwriting metric to the decision it supports: coverage ratios test cash flow adequacy, debt yield tests loan size against income, the loan constant reveals amortization effects, and call protection shapes exit economics. Practice with worked case numbers, extract term-sheet facts in a fixed order, and log every calculation error by concept rather than by question.
Why DSCR and debt yield answer different sizing questions
Debt service coverage ratio measures whether a property's net operating income covers the scheduled payments on a specific loan at its specific rate. Debt yield measures NOI against loan amount with no rate input at all. They can disagree, and the disagreement is the analytical signal.
Because DSCR embeds the interest rate and amortization schedule, a loan written at a low coupon can show comfortable coverage even when the loan balance is aggressive relative to income. Debt yield strips those financing terms out and asks a simpler question: if the lender had to take the property back, what return does the income represent on the dollars lent? That is why many lenders apply a minimum debt yield test alongside DSCR, and why a scenario can pass one test while failing the other.
Treat divergence between the two metrics as a prompt to investigate, not a rounding problem. When DSCR looks acceptable but debt yield is thin, the financing terms are doing the work; a refinance at higher rates or an amortizing payment later in the life of the loan could strain coverage. When debt yield is strong but DSCR is tight, the issue is usually a short amortization or high constant, which a longer schedule or interest-only structure might change. Naming which metric is driving which conclusion is the habit to build.
The table below contrasts the three core sizing metrics so you can decide, for any fact pattern, which test each number actually satisfies.
- DSCR: NOI divided by annual debt service; rate- and amortization-sensitive.
- Debt yield: NOI divided by loan amount; independent of financing terms.
- LTV: loan divided by value; governs collateral exposure, not cash flow.
| Metric | Formula | Sensitive to | Primary question answered |
|---|---|---|---|
| DSCR | NOI / annual debt service | Rate, amortization, interest-only periods | Can the property cover the payments on this loan? |
| Debt yield | NOI / loan amount | Loan size only | How does income compare to dollars lent, regardless of terms? |
| LTV | Loan amount / value | Appraisal or value basis | What collateral cushion protects the lender? |
How the loan constant and amortization shape every DSCR you compute
The loan constant is annual debt service divided by loan amount. It rises with shorter amortization and higher rates, and it changes when an interest-only period ends. Any DSCR conclusion depends on which constant you actually used.
Work the mechanics until they are automatic. A 30-year amortization at 6 percent produces an annual constant of roughly 0.0719, so a $14,000,000 loan carries about $1,007,000 of annual debt service. Shorten the amortization to 20 years at the same rate and the constant rises to roughly 0.0860, adding well over $100,000 of annual payments on the same balance. In a case scenario, the amortization line on the term sheet can move DSCR more than the rate line does, which is why reading it first pays.
Interest-only periods create a second trap: during the IO window, debt service excludes principal, so DSCR is computed on interest alone and reads artificially high. A well-built scenario will show coverage at closing, coverage after amortization begins, and coverage at maturity, because payment shock is the real risk. When you analyze any structured loan, compute the DSCR in each period: IO period, early amortization, and final year. If the scenario gives you a maturity date with a balloon, ask what refinancing conditions would need to hold for the balance to be retired.
Worked scenario one: sizing a loan when the metrics conflict
A borrower requests $14,000,000 against a property with $1,200,000 of NOI. At 5.5 percent with 30-year amortization, DSCR passes but debt yield falls short. The better decision sizes the loan on the binding test and explains the trade-off.
Run the numbers. Annual debt service at 5.5 percent over 30 years uses a constant near 0.0681, giving about $954,000 of payments; DSCR is $1,200,000 / $954,000, or roughly 1.26, which clears a typical 1.25x coverage requirement. Debt yield, however, is $1,200,000 / $14,000,000, or 8.57 percent, which fails a 9 percent minimum. The plausible mistake is to declare the loan approvable on DSCR alone and move on, never checking the second test because the first one passed.
The stronger response is to identify which test binds and resize: $1,200,000 / 0.09 equals a maximum loan of about $13,333,000, which restores debt yield while keeping DSCR at roughly 1.32 because debt service falls with the balance. Note that these thresholds are illustrative for the exercise, and actual lender minimums vary by loan program and property type. Why it matters: the low coupon made the original request look safe on coverage, but the rate-independent test revealed that the income did not support the full balance, which is exactly the kind of layered reasoning a case question rewards.
Worked scenario two: call protection versus the borrower's exit plan
Two quotes with similar rates can carry very different prepayment costs. Match the call protection structure to the borrower's expected holding period before comparing headline pricing, and quantify the premium in the scenario's own terms.
Consider a 10-year fixed-rate loan at 6 percent with yield maintenance, where the borrower discloses a possible portfolio sale in year 4. If rates at that point sit near 4.5 percent and the balance is about $9,500,000, the borrower effectively owes the lender the excess of 6 percent coupons over reinvestment rates for the remaining six years; a simplified discounted estimate of that excess interest runs into several hundred thousand dollars. Defeasance, the alternative structure, replaces the loan collateral with a portfolio of securities that reproduces the payment stream, and its costs and flexibility profile differ, so the two options are not interchangeable in a fact pattern.
The plausible mistake is comparing only the stated interest rates and recommending the lower one, ignoring that the expected early sale converts the cheaper-looking quote into the more expensive outcome. The better decision estimates the prepayment cost under the scenario's stated exit assumptions, compares it against the alternative structure's costs, and presents the effective cost over the expected holding period. Why it matters: commercial loans are priced as a package of rate, term, and exit rights, and a case question that names a likely sale or refinance is handing you the fact that should drive the recommendation.
Reading a term sheet: extract facts in a fixed order
Interpretation questions reward a consistent extraction sequence. Pull loan amount, rate basis, amortization, term, interest-only period, call protection, recourse, and reserves first, then compute. Also distinguish a term sheet from a commitment.
A term sheet is a non-binding summary of proposed terms used to align parties, while a loan commitment is a binding offer with conditions, and the application stage gathers the documentation behind the numbers. Scenario writers can describe documents loosely, so classify what you are reading before you rely on it: if the language says the terms are indicative and subject to committee approval, treat it as a term sheet, and note which figures are missing or marked as assumptions. Missing amortization or reserve language is itself a finding worth stating in your answer.
Use a fixed checklist so nothing is skipped under time pressure: amount, rate type with index and margin, amortization schedule, loan term, any interest-only period, prepayment or call protection, recourse and guarantee structure, escrow and reserve requirements, and covenants such as reporting or financial maintenance tests. Then compute debt service, DSCR, debt yield, and LTV from the extracted figures rather than from any summary sentence in the narrative, because a scenario can include a character's flawed characterization of the loan that your own calculation should confirm or correct.
- Extract: amount, rate basis, amortization, term, IO, call protection, recourse, reserves.
- Compute: annual debt service, constant, DSCR, debt yield, LTV.
- Classify the document: term sheet, application, or binding commitment.
Self-check exercise: rebuild a term sheet from raw numbers
Write a one-page hypothetical term sheet for a mixed-use property, then rebuild every metric from it and grade yourself with the rubric below. The goal is fluency in moving between document language and calculations.
Draft terms such as a $6,500,000 loan at 6.25 percent, 25-year amortization, 5-year term, 12 months interest-only, yield maintenance for years 1 through 4, carve-out-only recourse, and tax, insurance, and replacement reserves. Assume NOI of $520,000 and a $9,000,000 value. Compute annual debt service during and after the IO period, the constant in each period, DSCR in each period, debt yield, and LTV, then write two sentences on which test binds and what the IO expiry does to coverage in year 2. Repeat with a second draft that changes only the amortization to 20 years and observe how the binding test moves.
Grade your work with this rubric, treating scores as learning milestones rather than predictions of any exam outcome: two points for a debt service figure that is correct in both the IO and amortizing periods; two points for DSCR computed separately for each period rather than once; two points for debt yield and LTV computed from the stated NOI and value; two points for correctly identifying the binding constraint; two points for a written explanation that ties the IO expiry to the coverage change. Ten out of ten with both drafts indicates the concept is holding; anything lower tells you which specific calculation to drill next.
An adaptable preparation sequence with readiness checks
Structure preparation as concept fluency, calculation drills, scenario practice with an error log, then timed integration. Adjust the calendar to your schedule; keep the stages and their readiness checks in order.
In the first block, build concept fluency: define DSCR, debt yield, LTV, loan constant, yield maintenance, defeasance, recourse versus carve-out guarantees, and reserve types, and write one sentence on the decision each supports. In the second block, drill calculations until debt service, constant, DSCR, and debt yield each take well under a minute by hand or with a basic calculator. In the third block, work case-style scenarios, including the two above, and keep an error log keyed to concepts, such as 'used IO-period DSCR at maturity,' rather than to individual questions, so patterns become visible.
In the final block, integrate under time: read a full hypothetical term sheet, extract facts in your fixed order, compute all metrics, and write a short recommendation naming the binding constraint and the exit-cost consideration. Readiness checks before you finish: you can compute all four sizing metrics from any term sheet without notes; you can explain in two sentences why DSCR and debt yield can disagree and what each implies; your error log shows no repeated concept errors across your last several scenarios; and you can classify a document as term sheet, application, or commitment from its own language. These are self-assessed milestones, not guarantees of results.
One administrative note: eligibility rules, scheduling, fees, and exam logistics are set by the credential issuer. Confirm those details directly with the Mortgage Bankers Association education pages rather than relying on secondary summaries.
References and further reading
Use these references to explore the concepts and check the latest information from the relevant organizations.