A fully amortized payment is a payment paying back both interest and principal due each month which, if maintained unchanged through the remaining life of the loan at the then-existing interest rate, will pay off the loan over the remaining life.

This will reduce the loan balance based on a 15, 30 or 40 year payment schedule. Because you are paying back both principal and interest with your payment, your loan balance will go down over time. The Fully Amortized payment is calculated based on the greater of the Note Rate or Fully Indexed Rate (current index + margin).