Procedure Code

C4	CPT-4	American Medical Association, P.O. Box 10946, Chicago IL  60610.
C5	CPT-5	Deprecated.  There is no CPT 5th edition.  CPT-5 project added new codes to existing edition but did not create a new edition
HCPCS	CMS (formerly HCFA)  Common Procedure Coding System	HCPCS: contains codes for medical equipment, injectable drugs, transportation services, and other services not found in CPT4.
HPC	CMS (formerly HCFA )Procedure Codes (HCPCS)	Health Care Financing Administration (HCFA) Common Procedure Coding System (HCPCS) including modifiers.
I10P	ICD-10  Procedure Codes	Procedure Coding System (ICD-10-PCS.)  See http://www.cms.hhs.gov/ICD10/ for more information.
SCT	SNOMED CT	SNOMED procedure codes