The monthly payment can change after ten years and every year thereafter. After ten years, the required monthly payments will include both principal and interest in an amount sufficient to full amortize the unpaid principal, at the new interest rate, over the remaining term of the loan. The monthly payment will change every year based on the interest rate and the unpaid balance at that time. Changes in the monthly payment will occur one month following the interest rate change. The monthly payment could increase or decrease substantially depending on changes to the interest rate or principal balance. The monthly payment can also change during the initial 10-year interest-only period of the loan. Payment amounts that exceed the interest due for the prior month will reduce the principal balance. The reduction in principal balance may reduce the amount of the next payment. Escrow accounts to pay for real estate taxes and/or homeowners insurance may also create changes to the monthly payment amount.