What is the main difference between CPT and HCPCS Level I codes?

The main distinction between CPT codes and HCPCS Level I codes lies in the scope of the services they represent. CPT codes, developed by the American Medical Association, provide a comprehensive classification for a wide variety of medical procedures and services, particularly in outpatient settings. They cover not only surgical procedures but also evaluation and management services, diagnostic tests, and more.

On the other hand, HCPCS Level I codes are essentially identical to CPT codes because the HCPCS Level I system is derived directly from the CPT coding system. Therefore, while both systems encompass many of the same services and procedures, CPT codes offer a broader range of detailed classifications, particularly for outpatient scenarios.

The other options misrepresent the nature of the coding systems; for example, CPT codes are not limited to inpatient services, and they encompass more than just surgical procedures. HCPCS Level I also does not inherently include more modifiers than CPT codes, and both coding systems share a range of modifiers utilized for various circumstances. Thus, recognizing the uniqueness of CPT's more elaborate procedural classification helps clarify this key difference.