Claim Attending Physician UPIN Number

On an institutional claim, the unique physician identification number (UPIN) of the physician who would normally be expected to certify and recertify the medical necessity of the services rendered and/or who has primary responsibility for the beneficiary's medical care and treatment (attending physician).

NPIs replaced UPINs as the standard provider identifiers beginning in 2007. The UPIN is almost never populated after 2009.