ARM Conversion Option

What Is an ARM Conversion Option?

An ARM conversion option is a clause associated with some adjustable-rate mortgages (ARMs) that allows the borrower to convert the variable interest rate to a fixed rate within a certain time period or at certain future dates.

Key Takeaways

  • An ARM conversion option is a provision in an adjustable rate mortgage (ARM) allowing the borrower to convert the variable rate to a fixed interest rate for the remaining term of the loan.
  • Convertible ARMs are marketed as a way to take advantage of falling interest rates and usually include specific conditions and limitations.
  • Lenders generally charge a fee to switch the ARM to a fixed-rate mortgage, as well as a larger ARM margin during the variable period.

How ARM Conversion Options Work

An ARM with a conversion option is called a convertible ARM. Introduced in the early 1980s, convertible ARMs entered the scene during a period of double-digit fixed-rate mortgages. The theory was that because interest rates were historically unlikely to go much higher (barring extraordinary inflation), borrowers of convertible ARMs could essentially bet on the greater likelihood of lower rates in the future.

However, early convertible ARMs were quite expensive and contained onerous restrictions. And while they have grown more competitive, even today, the conversion option is not free. An ARM with a conversion option will typically have a higher ARM margin rate (and, therefore, a higher fully indexed interest rate) or higher costs than ARMs without a conversion option.

Pros and Cons of an ARM Conversion Option

Some might say that ARMs with conversion options offer the best of both interest-rate worlds: the chance to move with market rates but also to lock in a steady rate.

The main pro comes if an interest-rate decline is on the horizon. The convertible ARM offers a way to reap the benefits of falling interest rates—and to lock them in, early in the life of the loan.

The option to convert often is within the first one to five years of the mortgage term.

That’s part of the challenge, though. Taking advantage of the ARM forces the borrower to monitor interest rates and predict their future path, something that even financial pros don’t always do reliably. And you might have to move fast: Your new fixed interest rate is determined based on the lowest rate within a week of your final decision to convert.

Also, even though opting for a lower interest rate seems like a no-brainer, the numbers don’t always add up. Remember: A fee must often be paid to convert to the fixed rate, and the fixed rate to which the ARM is converted is typically based upon the general market interest rate at the time of conversion plus a certain percentage. If future refinancing costs are estimated to be less than the total costs of the conversion option, then the conversion option is not economical. The borrower would be better off with a traditional ARM with the intent to refinance into a fixed interest rate at a future date.

Also, in virtually all cases, the fixed rate that you receive after converting will be somewhat higher than what you initially paid on your ARM (especially if you’re still in the super-low teaser rate period that most ARMs offer).

To analyze the economics of a conversion option, borrowers should total up the cost of the convertible ARM (an initial higher interest rate and/or higher loan costs than with regular ARMs) plus the cost of the actual conversion to a fixed rate. Then, compare this sum to the costs of refinancing into a fixed interest rate at a future date.

When to Use an ARM Conversion

If a sharp interest-rate tumble seems imminent—if the Federal Reserve (Fed) seems likely to cut the federal funds rate, for example—then it might be a good time to convert your ARM. The Fed sets this rate eight times a year; if possible, you could wait a few months, to see if a general rate-slashing trend is under way. Naturally, you would want to lock in when interest rates are at their lowest.

In low-interest-rate environments, ARMs with conversion options tend to be less attractive to many borrowers. If inflation—and a rise in interest rates—is running rampant, though, they grow more appealing.

You’ll also want to compare the general interest rate with your loan’s teaser rate—if you’re still in the latter—and with when your ARM’s interest rate will reset.

Along with interest rate trends, consider your personal situation and whether a fixed rate makes sense. People often opt for ARMs when they plan to be in a home for a limited, fairly short term (usually before the interest rate reset sets in). If that’s still the plan, then it’s likely not worth the cost to convert. However, if you think that you will remain in the residence for a while after all, then invoking the conversion might make good sense.

Remember, borrowers are generally allowed to invoke their conversion option clause within the first five years of their mortgage, so make sure any moves coincide with the time frame.

Special Considerations

Conversion options also exist in insurance policies.

A conversion option, from the context of the insurance industry, can refer to a clause that allows the policyholder to change a term life insurance policy into a whole life policy. Exercising such an option in most cases will incur additional costs for the policyholder. Furthermore, there may be a specific window of time when such a conversion can be requested. A policyholder might choose to convert to guarantee coverage beyond the limits of the term policy for which they originally signed up.

Under a whole life policy, they might also neither have to submit evidence that they are in sound health nor agree to medical examinations. Having term life insurance with a conversion option clause can be an alternative to paying for a whole life policy from the start, which would include even higher premiums for the policyholder to pay.

A conversion could also be necessary if an individual was covered by group insurance through an employer and, after separating from the company, wants to switch the policy for which they have been paying to an individual life insurance policy.

Conversion options can also be found in health insurance—for example, with options for a policyholder to change their critical care coverage from a standard policy to one that specializes in long-term care at private facilities.

How does a convertible mortgage work?

A convertible mortgage, officially a convertible adjustable-rate mortgage (ARM), is an ARM that borrowers can convert to a fixed-rate mortgage at a later date (generally within the first five years of the loan). The new, fixed interest rate reflects prevailing markets, plus a percentage. Lenders usually charge a fee to convert or switch the ARM to a fixed-rate mortgage.

Why would you want a convertible mortgage agreement?

No matter what the initial interest rate is, a convertible mortgage gives the borrower the option to lock in an even better one. By allowing a switch from a variable interest rate to a fixed rate, the convertible mortgage lets borrowers take advantage of a general decline in interest rates. And they don’t have to worry about the bother or cost of refinancing their loan (though they do pay a fee to convert). 

Article Sources
Investopedia requires writers to use primary sources to support their work. These include white papers, government data, original reporting, and interviews with industry experts. We also reference original research from other reputable publishers where appropriate. You can learn more about the standards we follow in producing accurate, unbiased content in our editorial policy.
  1. Rocket Mortgage. “Convertible ARM Loan: Is It Right For You?” Accessed Oct. 4, 2021.

Compare Mortgage Lenders
The offers that appear in this table are from partnerships from which Investopedia receives compensation. This compensation may impact how and where listings appear. Investopedia does not include all offers available in the marketplace.