With the rollout of the Recovery Audit Contractor (RAC) audit program in full swing, physicians should be paying close attention to their medical record documentation efforts. One of the Medicare documentation requirement that many physicians don’t fully appreciate is the requirement that all medical records be signed by the performing physician. Specifically, Medicare requires that medical records include a "legible identifier" for all services provided/ordered. According to the Medicare medical review documentation standards, the legible identifier must be in the form of a hand written or electronic signature (stamp signatures are not acceptable). The medical review documentation standards can be found at Section 188.8.131.52 of the Medicare Program Integrity Manual.