The CASS (Coding Accuracy Support System) Certification Flag is in the MASTER file (field MCCTL) and can have the following values:
- 0 = No maintenance done since last CASS Certification
- 1 = Maintenance done on the address since last CASS Certification
- 9 = Do not certify this address
Refer to the "Understanding the CASS Monitoring Flag" section of the CASS Certification Procedures booklet (see the link below) for details on how this flag is used and maintained.