Loans in which the interest rate is fixed, but the payment rises according to a pre-set schedule. These are called graduated payment mortgages because the payments are increased each year during the early life of the loan. The effect is to reduce the payment level in the first few years and to increase it somewhat in the middle and later years. The GPM is intended for young homebuyers whose relatively low income is expected to grow over the years. The predetermined amount of change in the payment is not dependent on the movements of an index, although there are loans which combine the features of the GPM and the ARM. The common type of GPM involves negative amortization for the first several years.