Which code system is used for classifying medical diagnoses?

The International Classification of Diseases (ICD) is the correct choice for classifying medical diagnoses. This coding system is designed specifically to provide standardized codes for the diagnosis and classification of diseases and health-related issues. Used worldwide, the ICD allows healthcare providers to document patient diagnoses consistently and facilitates the process of tracking healthcare statistics, billing, and research on morbidity and mortality.

ICD codes are essential for ensuring that there is a uniform understanding among healthcare practitioners and entities regarding a patient's diagnosis, which in turn supports appropriate treatment plans and facilitates accurate medical record-keeping. This standardization is important for the effectiveness of healthcare systems, insurance claims processing, and public health surveillance.

In contrast, the Current Procedural Terminology (CPT) is primarily focused on coding medical procedures and services rather than diagnoses. The Healthcare Common Procedure Coding System (HCPCS) also generally deals with procedures, facilities, and equipment, while the National Drug Code (NDC) specifically identifies drugs rather than medical diagnoses. Thus, ICD stands out as the essential system for documenting and classifying medical diagnoses effectively.