An annualized rate of default on a group of mortgages, typically within a collateralized product such as a mortgage-backed security (MBS). The constant default rate represents the percentage of outstanding principal balances in the pool that are in default, which typically equates to the home being past 60-day and 90-day notices and in the foreclosure process. 

The constant default rate analysis assumes that if a home is in foreclosure (a process that can take 12 months or more to complete), the interest and principal payments are being advanced into the MBS by the mortgage servicing company. 





|||The CDR method for evaluating losses is one of several methods used by analysts and company controllers to determine the current market value or asset value of a mortgage-backed security. The CDR method can account for both fixed-rate and adjustable-rate mortgages. 

Another method is the Standard Default Assumption (SDA) model created by the Bond Market Association, but this is more suited to standard 30-year fixed mortgages. In the mortgage crisis of 2007-2008, the SDA model proved to have vastly underestimated the true rate of default; foreclosure rates hit multi-decade highs during that period.