WPS Medicare is aware that the CERT Review Contractor (CRC) may assess an error when medical record documentation does not include a legible identifier of the author. The CRC confirmed that the Office of Inspector General has made it clear that the signature must be legible. To avoid potential assessment of CERT errors for this reason, WPS Medicare recommends that providers make certain their signature is legible, and include a signature sample when responding to CERT Documentation Contractor (CDC) requests for medical records. The legible identifier requirement applies to documentation for any service performed and billed to Medicare.