An interest-only mortgage is a mortgage with scheduled payments that require the consumer to have:

With an interest-only mortgage, the borrower makes payments that cover only the interest for a set period (such as 5 or 10 years). After this period, the borrower begins paying both principal and interest, which causes payments to increase.

“An interest-only mortgage is a loan with scheduled payments that for a period of time require payment of interest only, with no reduction of the principal balance.”

— CFPB, Consumer Handbook on Adjustable-Rate Mortgages; SAFE MLO National Test Study Guide