Single Monthly Mortality Rate (SMM) Law and Legal Definition
Single Monthly Mortality Rate (SMM) is the percentage of a mortgage loan principle paid by one monthly installment. SMM is the amount of monthly principal reduction in excess of a scheduled monthly principal payment. SMM is expressed as a percentage of the principal balance at the beginning of a month. SMM is equal to the unscheduled prepayments during a month divided by the scheduled balance for the end of the month expressed as a percentage
