Certified Coding Associate Exam Study Guide 2026

'See also' in the Alphabetic Index directs the coder to another main term that may provide additional or alternative code options.

The Current Procedural Terminology (CPT) code set is specifically designed for reporting medical, surgical, and diagnostic procedures and services performed by physicians and other healthcare providers. For outpatient coding, where services are often procedure-based, CPT codes are the primary system used to describe the work performed. ICD-10-CM codes are used for diagnoses, while ICD-10-PCS is for inpatient procedures, and HCPCS Level II covers non-physician services and supplies.

ICD-10-PCS (Procedure Coding System) is the classification system mandated for coding inpatient hospital procedures in the US.

The International Classification of Diseases (ICD) code sets, including ICD-10, are developed and maintained by the World Health Organization (WHO). The WHO is responsible for the global standard of disease classification. In the United States, the Centers for Disease Control and Prevention (CDC) and the Centers for Medicare & Medicaid Services (CMS) are responsible for clinical modifications (like ICD-10-CM) and official guidelines.

For outpatient visits, the condition chiefly responsible for the visit (after study) is sequenced as the first-listed diagnosis per UHDDS guidelines.

A Clinical Documentation Improvement (CDI) specialist plays a crucial role in ensuring accurate medical documentation. They work collaboratively with physicians and other healthcare providers to improve the quality, completeness, and specificity of clinical records. This enhanced documentation directly supports accurate medical coding, which is essential for proper reimbursement and patient care.