At the baseline, your monthly mortgage bill covers the interest you owe that month and a part of your principal. But there are other monthly costs to consider. If you have created an escrow account that automatically pays for your homeowners insurance and property taxes, they will be calculated into your mortgage payment. If you live in a house or building with a Homeowners Association, you will have to pay monthly fees. If you had to get PMI, the monthly premium will be part of your mortgage payment.