CPT®, HCPCS, And ICD-10-CM: The Crazy, Mixed-Up World Of Medical Code Sets

The five-second explanation of physician code sets is that CPT® represents procedures, HCPCS represents supplies, and ICD-10-CM represents diagnoses. But the reality is a little bit messier. Here are some exceptions the code sets throw in that are sure to keep you on your toes.

CPT®: It’s Not Just for Procedures

CPT® stands for Current Procedural Terminology. The codes generally cover services and procedures. But veterans of medical coding companies and healthcare business offices know that CPT® doesn’t always stay in its own “procedure” lane.

Key example: Codes 90476-90749 represent vaccines and toxoids. In other words, those CPT® codes are for the product supply. You use a separate code to report the administration of the vaccine or toxoid product. (The CPT® guidelines point you to CPT® administration codes 90460-+90474, but of course, it’s not that simple. That’s the point of this article. See more about that in the HCPCS section.)

The fact that code sets don’t have strict limits is one reason why online medical billing software and online medical coding tools can be so useful. The ability to search multiple code sets simultaneously cuts down on your medical code lookup time, and who doesn’t want that?

CPT®, HCPCS, And ICD-10-CM: The Crazy, Mixed-Up World Of Medical Code Sets

HCPCS: So Much More Than Supplies

Level II HCPCS codes often get described as drug and supply codes, but that’s not all they are. To be fair, HCPCS does stand for Healthcare Common Procedure Coding System, and CPT® codes are actually Level I HCPCS codes. So maybe it’s not that surprising that the Level II HCPCS codes, usually referred to simply as HCPCS codes, include plenty of codes beyond medical and surgical supplies, durable medical equipment, and drugs.

For instance, ss mentioned above in the CPT® section, there are vaccine administration codes in the HCPCS code set. Medicare requires you to use the admin codes it created rather than using codes from the CPT® code set. And vaccine administration isn’t the only area where coders need to be on alert for HCPCS codes to use in place of CPT® codes. Even common services like Pap tests and colorectal cancer screening by fecal occult blood test have HCPCS codes to use when reporting to Medicare.

Having separate codes like this allows Medicare to provide their own descriptors aimed at collecting specific data. Private payers may accept those HCPCS codes, too, or even add their own codes in the S code section. Having two code sets to check for the same service makes knowing the nuances of coding for your specialty essential to producing accurate claims!

Tip: Don’t forget about quality measure codes. Programs like MIPS may use HCPCS codes (or Category II CPT® codes) to collect data for individual measures.

ICD-10-CM: The D is for Diseases, Usually

ICD-10-CM stands for International Classification of Diseases, Tenth Revision, Clinical Modification. The CM is important because it clarifies you’re not talking about ICD-10-PCS, the procedure coding system inpatient facilities use.

But not every code in ICD-10-CM represents a disease or even an injury. There are codes that identify the patient’s status (even healthy patients) or give details to explain why a patient presented to the healthcare provider. Here are just a few examples.

  • Encounter codes like Z00.00 (Encounter for general adult medical examination without abnormal findings)
  • Status codes like Z18.2 (Retained plastic fragments)
  • External cause codes, too, with interesting options to explore, like W59.22XA (Struck by turtle, initial encounter).

Bottom line: Be sure you understand everything each code set has to offer. There may be times when a payer requires a HCPCS code instead of a CPT® code for a procedure you report, there may be times when CPT® gives you a way to report supply, and there may be times when you can enhance a claim for an injury by specifying that the patient was struck by a turtle.