Convertible ARMS, which can be replaced by a fixed-rate loan later in the term of a loan.
The numerically titled 5/25-7/23 loans begin as 30-year fixed-rate loans. But after the first five- to- seven years, they can be converted to ARMs.
Convertible ARMs can be converted to a fixed rate in later years.

A Graduated Equity Mortgage (GEM) resembles a 25-year fixed-rate loan but requires higher principal repayments.
Graduated Payment Mortgages (GPMs) begin with low monthly payments that gradually increase, appealing to borrowers with rising income expectations.