When financing your home, you’ll not only need to choose a mortgage lender, but you’ll also need to choose between a fixed-rate or adjustable-rate mortgage (ARM). With a fixed-rate mortgage, the interest rate on your loan will never change. With an ARM, the rate will change at regular intervals up to a preestablished interest rate cap.
While an ARM can be a good mortgage option, some homeowners avoid this type of financing over concerns about how much their payments might increase. Interest rate caps can help ease this worry by setting limits on how much the rate can change at each adjustment period and in total over the life of the loan.
An interest rate cap is used on an adjustable-rate mortgage to limit how much the interest rate can change initially, periodically and over the life of the loan.
Jump to insightThe three types of interest rate adjustment caps are called the initial, subsequent and lifetime caps.
Jump to insightARMs are generally best for people who don’t plan to keep their home long or people who are more concerned with lower initial monthly payments and plan to eventually refinance.
Jump to insightWhat is an interest rate cap?
An interest rate cap limits how much the interest rate can increase or decrease on an adjustable-rate loan. Interest rate caps are most commonly used with adjustable-rate mortgages. They establish limits on how much the loan rate can increase or decrease initially (the first time the rate adjusts), on subsequent adjustments and over the life of the loan (the total increase).
There are three types of interest rate caps: initial adjustment, subsequent adjustment and lifetime adjustment.
Risks and benefits of interest rate caps
One of the biggest concerns with a variable rate on a mortgage or another type of installment loan is how much your payment might change when the interest rate resets. A benefit to an adjustable-rate loan is the potential for your payment to decrease if rates are lower at the change date. Conversely, your payment might increase in a rising interest rate environment.
Interest rate caps protect borrowers during a rising rate environment, since they establish the maximum amount the rate can change. Because interest rate caps are defined in your loan documents, you can do the math to determine the maximum principal and interest payment you might have to make on your loan.
What does an interest rate cap mean for ARMs?
With an ARM, the rate stays the same for an initial period and then changes at set intervals (for example, once per year). This differs from a fixed-rate mortgage, where the interest rate never changes. Besides defining how frequently the rate changes, ARMs also include limits on how much the rate can increase each time and in total over the life of the loan, which are known as interest rate caps.
Jay Dacey, president of Jay Dacey Mortgage Team, a broker based in St. Paul, Minnesota, explained that ARMs typically carry three separate interest rate caps: the initial adjustment cap, the annual (periodic or subsequent) cap and the lifetime cap.
These three interest caps provide homeowners with ARMs the protection they need against future interest rate increases.
- Initial interest rate adjustment cap: The initial adjustment cap limits the amount your rate can increase or decrease at the first adjustment period, and it’s often 2% to 5%. This means if your loan started at a 5% rate, the most it could increase at the first adjustment period is to a maximum of 7% to 10%.
- Subsequent interest rate adjustment cap: The subsequent cap limits how much your rate can increase or decrease at the following adjustment periods, and it’s most often 1% or 2%. If the cap is 2% and your rate adjusts to 7% at the first adjustment period, 9% is the highest possible rate you can subsequently have.
- Lifetime interest rate adjustment cap: The lifetime cap limits the total amount your rate can increase or decrease over the life of the loan. If you have a lifetime cap of 5% (a common cap) and your initial rate is 5%, future increases could never take your rate higher than 10%.
As you shop for an ARM, consider both the initial interest rate and the rate caps. Even if two lenders offer you the same initial interest rate, the potential for future rate increases may be vastly different depending on the interest rate caps.
» MORE: Mortgage APR vs. interest rate
When should you consider an ARM?
You might want to consider an ARM if you plan on selling your home or refinancing your loan before the loan’s initial rate period ends, if interest rates are high when you buy your home or if the potential for a higher payment in the future doesn’t concern you.
“Homeowners should consider an ARM when they are confident they will not keep the mortgage [for] more than a few years, or [if] they are most concerned about the monthly payment versus the long-term risk of an adjustable rate,” said Eric Jeanette, CEO of Dream Home Financing, a mortgage broker.
According to Jeanette, a key advantage of an ARM versus a traditional fixed-rate mortgage is the ability to receive a lower interest rate initially. “This means there will be a lower payment and the ability to stretch out your buying power,” Jeanette said.
However, one of the key concerns associated with ARMs is how much the interest rate might increase at each adjustment period. Your lender must share details about the interest rate caps with you during loan origination. You can ask the lender to calculate the highest possible monthly payment you might need to make under the loan terms.
“The standard interest rate cap for adjustable rate mortgages is 2-2-6,” Jeanette said. “This means the most the interest rate can increase at the first adjustment period is 2%, the most the rate can increase at any subsequent adjustment period is 2%, and the most the rate can increase over the life of the loan is 6%.”
Ultimately, if you don’t think your budget can support the maximum potential payment, you might want to consider getting a fixed-rate mortgage instead of an ARM.
Current conventional national mortgage rates
Rates are effective 05/15/2026 and are subject to change without notice. APR shown is provided by a partner of ConsumerAffairs.
| Product | APR | |
|---|---|---|
| 7.48%0.17% | Get Rates | |
The initial APR shown of 7.480% is available for a 5-year adjustable rate mortgage in the amount of $200,000 for consumers with loan-to-value of at least 80%. APR may be subject to change per loan terms. | ||
| 6.977%0.0% | Get Rates | |
The initial APR shown of 6.977% is available for a 7-year adjustable rate mortgage in the amount of $200,000 for consumers with loan-to-value of at least 80%. APR may be subject to change per loan terms. | ||
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FAQ
How is the rate calculated on each change date?
The new rate on an ARM is set by adding two factors: the margin, which is the number of percentage points that’s set in the loan agreement, and the benchmark index rate, which is the benchmark index that’s chosen by your lender and changes based on market conditions. The rate can’t increase by an amount that’s greater than the adjustment cap, and it can’t go over the lifetime cap.
Can I convert my ARM to a fixed-rate mortgage?
You can convert an ARM to a fixed-rate mortgage by refinancing your home loan. This is a common strategy among homeowners when interest rates are low.
What is the start rate on an ARM?
The start rate on an ARM is known as the loan’s initial interest rate. While the initial rate most commonly lasts five years, it could be shorter or longer, depending on the terms of your loan. The initial rate on an ARM is often lower than the rate on a fixed-rate mortgage.
How is the cost of an interest rate cap determined?
The cost of an interest rate cap is generally determined by the notional amount (the loan amount), the term (how long the cap is for), the strike rate (which sets the maximum interest rate) and market conditions. Typically, larger loan amounts and longer terms will cost more than smaller loan amounts and shorter terms.
Which is better: a fixed-rate mortgage or an adjustable-rate mortgage?
If you’re concerned about the affordability of a loan payment should interest rates increase, you might be better off choosing a fixed-rate loan instead. If you already have an ARM, you might consider refinancing to a fixed-rate loan when interest rates are low or are expected to increase.
Bottom line
Interest rate caps limit how much the interest rate on an ARM can increase initially, regularly and in total. These caps make it possible to know your maximum possible monthly mortgage payment before you decide on an adjustable-rate home loan.
Carefully review your mortgage offer before moving forward, and consider your financial situation and how your mortgage payments might change. If you’re unsure which mortgage is right for you, it’s a good idea to consult with a mortgage professional.
Article sources
ConsumerAffairs writers primarily rely on government data, industry experts and original research from other reputable publications to inform their work. Specific sources for this article include:
- Consumer Financial Protection Bureau (CFPB), “What Are Rate Caps With an Adjustable-Rate Mortgage (ARM), and How Do They Work?” Accessed Nov. 10, 2025.
- CFPB, “For an Adjustable-Rate Mortgage (ARM), What Are the Index and Margin, and How Do They Work?” Accessed Nov. 10, 2025.
- Fannie Mae, “Interest Rate Caps.” Accessed Nov. 10, 2025.
