Mortgage Assumption Value

The mortgage assumption value (MAV) is the cash equivalent, at the current point in time, of all future savings that could be achieved by assuming an existing low-interest-rate home mortgage loan rather than taking out a new higher interest rate loan and accounting for the time value of money. This value is associated with a specific mortgage and fluctuates as currently, available interest rates vary relative to the subject mortgage.

Source: Wikipedia — Mortgage Assumption Value (CC BY-SA 4.0)