The official coding authorities for outpatient and provider services are based on the code sets used in that setting. Diagnoses are coded using ICD-10-CM, guided by the ICD-10-CM Official Guidelines and AHA Coding Clinic for ICD-10-CM. Procedures and services are coded using CPT® and HCPCS Level II. Therefore, the official guidance for those code sets—the American Medical Association's CPT Assistant and the American Hospital Association's Coding Clinic for HCPCS—are the other primary sources of coding authority.

B. The ICD-10-PCS Official Guidelines are for inpatient hospital procedure coding only and are not applicable to outpatient services.

C. ICD-10-PCS and DRG Expert are resources for the inpatient setting, not outpatient/provider services. DRG Expert is also a commercial tool, not an official authority.

D. This option incorrectly includes multiple resources (ICD-10-PCS Guidelines, DRG Expert) that are exclusively for the inpatient setting.

1. American Medical Association (AMA). (Current Year). CPT® Professional Edition. Introduction section. This section establishes the CPT Assistant as the official source for CPT coding guidance.

2. American Hospital Association (AHA). (Current Year). AHA Coding Clinic® for HCPCS. The publication itself is the official source for guidance on the use of HCPCS Level II codes.

3. ICD-10-PCS Official Guidelines for Coding and Reporting, FY 2024. Introduction. "The ICD-10-PCS is a procedure classification published by the United States for classifying procedures performed in hospital inpatient health care settings."