A NOTE ABOUT PRIVATE MORTGAGE INSURANCE Mortgage insurance is required primarily for borrowers with a down payment of less than 20% of the home's purchase price. It protects lenders against some or most of the losses that can occur when a borrower defaults on a mortgage loan. In the chart below, the monthly PMI (Private Mortgage Insurance) amount/rate may not be known until you have received a Mortgage PreApproval. For PreApproval information, select "GET PRE-APPROVED" in the drop down option under the Loan Calculator tab.