I am often asked by providers of outpatient therapy services how to identify who the certifying physician/non-physician practitioner (NPP) or physicians/NPPs are on the claim form. The answer depends on whether you are a private practice submitting claims on the paper 1500 claim form or the electronic equivalent (i.e. 837P) or you are an institutional provider (i.e. skilled nursing facility, rehabilitation agency, CORF, or hospital outpatient department) submitting claims on the UB-04 electronic claim form (837I). In this article, I will provide the answers to the above including how to identify multiple physicians/NPPs on the claim form when one physician/NPP