What is an interest rate cap?
An interest rate cap limits how much the interest rate can increase or decrease on an adjustable-rate loan, such as an adjustable-rate mortgage. The cap establishes limits on how much the loan rate can increase or decrease the first time the rate adjusts, on subsequent adjustments and over the life of the loan.
What an interest rate cap means for ARMs
There are three types of interest rate caps: initial adjustment, subsequent adjustment and lifetime adjustment.
With an ARM, the rate stays the same for an initial period and then changes at set intervals, such as 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. For example, 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.
“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 06/30/2026 and are subject to change without notice. APR shown is provided by a partner of ConsumerAffairs.
| Product | APR | |
|---|---|---|
| 7.252%0.0% | Get Rates | |
The initial APR shown of 7.252% 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. | ||
| 6.665%0.0% | Get Rates | |
The initial APR shown of 6.665% 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 an 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, which is the loan amount
- The term, or how long the cap is for
- The strike rate, which sets the maximum interest rate
- 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, at each adjustment period 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, “What Are Rate Caps With an Adjustable-Rate Mortgage (ARM), and How Do They Work?” Accessed May 24, 2026.
- Consumer Financial Protection Bureau, “For an Adjustable-Rate Mortgage (ARM), What Are the Index and Margin, and How Do They Work?” Accessed May 24, 2026.
