2007 ICD-9-CM Procedure 51.1 Diagnostic procedures on biliary tract 51.1 is a non-specific code that should not be used to specify a procedure View the full Volume 3 51.* hierarchy 51.1 excludes: that for endoscopic procedures classifiable to 51.64, 51.84-51.88, 52.14, 52.21, 52.93-52.94, 52.97-52.98