During the fourth quarter, 148 CERT errors were assessed for all Part B contracts within J12. Of those 148 errors, 66 errors were due to insufficient documentation (error code 21), 47 were due to medical necessity (error code 25), 33 were due to incorrect coding (error code 31) and 2 were due to service billed were not rendered (error code 41). The majority of the errors for insufficient documentation were related to the fact that the medical record documentation did not contain a valid physicianâ€™s signature or the radiology report/diagnostic test did not contain a valid physician order or identification of the provider who rendered the service. The medical necessity errors consisted mainly of laboratory and/or diagnostic services which did not contain a physicianâ€™s order or valid requisition form in the documentation. Please remember when you receive a request for documentation from the CERT contractor, to submit any and all documentation that you have to support the service(s) billed to Medicare. It is important that this information include items such as progress notes, therapy notes, results of diagnostic and/or laboratory tests, AND physicianâ€™s orders and signatures. If you believe that the documentation is illegible, please provide transcription with your original notes when you send them to the CERT contractor.