CPT Code 90471: Immunization Administration Billing Guide 96372 CPT Code: Injection of drug substance under skin or into muscle CPT Code 96372 Guide Injection Coding Tips Compounded Cyanocobalamin (Vitamin B12) Injection Empower Injection and Infusion Coding: What You NEED to Know! Not all injections are created equal and in the CPT Medicine section, the difference between an IV infusion, an IM injection,