There are a few caveats to recasting, however. The first is that you may need to have a large sum on hand. JPMorgan Chase, for example, charges a $150 fee and requires a minimum $5,000 payment toward the principal.

Another issue is having a lender, or loan servicer, that offers the service. And even those that do may impose restrictions. JPMorgan Chase and Bank of America exclude loans backed by the Federal Housing Administration and the Department of Veterans Affairs, and loans that were sold off and securitized may also need investor approval.

While few if any lenders advertise recasting, “they are trying to become more customer-service-oriented, and they will do it on a case-by-case basis,” Mr. Rosenbaum said. Homeowners should contact their lender’s customer service department.

Lenders, which would probably rather earn thousands of dollars in closing fees from refinancing your loan, are not obliged to recast mortgages. And certain types of mortgages, for example interest-only and adjustable-rate loans, usually aren’t eligible. The borrower will also need to have been current with all mortgage payments to qualify.

Edward Ades, the owner of Universal Mortgage in Brooklyn, says recasting can be especially useful to recent buyers, for whom it makes little financial sense to refinance but who expect to receive a tax refund or other substantial money after closing on their property, like proceeds from a relative’s sale of property, stocks or other assets.

If your interest rate is 5 percent or lower, Mr. Ades added, it may not make sense to recast a loan, because the extra cash could be put into an investment with a higher return. “At the end of the day,” he said, “I always tell people they have to do whatever makes them sleep better.”