Understanding HECM Rates
Reverse Mortgage Interest Rates
How They Work and Why They Matter
The most important thing to understand about HECM rates
With a traditional mortgage, your interest rate determines your monthly payment. With a HECM reverse mortgage, there are no required monthly payments — so the rate serves a different purpose.
Your HECM interest rate affects two things:
1. How much you can access
A lower expected interest rate means a higher principal limit — you qualify for more money. Even a small rate difference can change your available proceeds significantly.
2. How fast the balance grows
Interest accrues on whatever you have borrowed. A lower rate means your loan balance grows more slowly, preserving more equity over time.
Adjustable rate vs. fixed rate HECM
About 95% of HECM borrowers choose adjustable-rate loans. Here is why — and when a fixed rate might make sense:
| Feature | Adjustable Rate HECM | Fixed Rate HECM |
|---|---|---|
| Payout options | Line of credit, monthly payments, lump sum, or any combination | Lump sum only |
| Rate structure | Index (CMT treasury) + lender margin; adjusts monthly or annually | Locked at closing for life of loan |
| Rate caps | Lifetime cap (typically 5% over initial rate for annual-adjust, 10% for monthly-adjust) | Rate never changes |
| Growing credit line | Yes — unused line grows at effective rate | No — full amount taken at closing |
| Best for | Most borrowers; flexibility, credit line growth, long-term planning | Large existing mortgage payoff or HECM for Purchase where full proceeds needed upfront |
| Market share | ~95% of all HECMs | ~5% of all HECMs |
How adjustable HECM rates are calculated
An adjustable HECM rate has two components:
Your Rate = Index + Margin
The index is a benchmark rate you cannot control — most HECMs use the Constant Maturity Treasury (CMT) rate, published daily by the U.S. Treasury. This moves with the broader interest rate environment.
The margin is your lender's markup, typically between 1.5% and 3.0%. This is set at closing and never changes for the life of the loan. The margin is where you have shopping power — different lenders offer different margins.
For example, if the 1-year CMT is 4.25% and your lender's margin is 2.0%, your rate would be 6.25%. If the CMT drops to 3.75% at the next adjustment, your rate becomes 5.75%.
The "expected rate" — what determines your borrowing power
When you apply for a HECM, HUD uses the expected rate to calculate your principal limit factor (PLF) — the percentage of your home's value you can access.
For adjustable-rate HECMs, the expected rate is the 10-year CMT plus your lender's margin. This forward-looking rate determines how much money you qualify for, regardless of what the current adjustable rate is.
Example: How rate affects borrowing amount
A 72-year-old with a $500,000 home might qualify for approximately:
At a 5.5% expected rate: ~$260,000 (52% PLF)
At a 6.5% expected rate: ~$230,000 (46% PLF)
At a 7.5% expected rate: ~$200,000 (40% PLF)
These are illustrative estimates. Actual amounts depend on current PLF tables, property value, and lender fees. Use the calculator for a personalized estimate.
A silver lining with higher rates: credit line growth
Here is something counterintuitive. When interest rates are higher, your HECM line of credit grows faster.
The unused portion of your HECM credit line grows at the effective rate (current interest rate + 0.5% ongoing MIP). In a higher-rate environment, while you may qualify for less initially, that credit line compounds more quickly — potentially giving you access to more money in later years when you may need it most.
This is one reason many financial planners recommend establishing a HECM line of credit early in retirement, even when rates are elevated. Learn more about credit line growth.
How to get the best HECM rate
You cannot control the index (it moves with treasury markets), but you can influence the margin:
Shop multiple lenders. Margins vary from lender to lender, and even a 0.5% difference in margin affects both your rate and your borrowing power. Request quotes from at least 2-3 HECM lenders.
Understand the margin-fee tradeoff. Some lenders offer a lower margin but charge higher upfront fees (like a larger origination fee). Others offer a higher margin but waive fees. Consider the total cost of the loan over your expected timeframe.
Timing matters, but do not try to time the market. If rates are favorable and a HECM fits your plan, moving forward makes sense. Waiting for rates to drop is a gamble — and if your situation calls for a reverse mortgage now, the benefits of acting outweigh marginal rate improvements.
Ongoing MIP: the other rate component
In addition to the interest rate, every HECM charges an annual mortgage insurance premium (MIP) of 0.5% on the outstanding balance. This is what funds the FHA insurance that protects both you and your heirs with the non-recourse guarantee.
Combined, your total effective rate on borrowed funds is: interest rate + 0.5% MIP. If your interest rate is 6.5%, your total effective rate is 7.0%.