The CMS-maintained alphanumeric code set for drugs, supplies, equipment and services that CPT does not describe.
One letter followed by four digits. The letter is the family: J for drugs administered other than orally, A for supplies and transport, E for durable medical equipment, Q and C for temporary and outpatient hospital codes, G for Medicare-specific services.
CMS updates the file quarterly. New drugs typically spend one to four quarters on a miscellaneous code before receiving a permanent one.