Definition: Sure, I'd be happy to explain the term "mortgage assumption" and provide a detailed definition. The term "mortgage assumption" refers to the process of creating an estimate of the value of a mortgage loan or security for a home equity loan or a home equity line of credit (HELOC). The purpose of this is to determine the amount that the borrower can borrow to make their monthly payments on the loan. This information is then used in determining the interest rates and fees associated with the loan. The term "mortgage assumption" typically refers to the process of estimating how much a home's value would be if the property were sold for an original purchase price, based on any changes in market values or inflation. The mortgage company uses this estimate to determine the rate of interest that the borrower will pay each month. In summary, the term "mortgage assumption" refers to the process of estimating how much a home's value would be if it were sold for an original purchase price, using information such as changes in market values or inflation.