Differentiate ICD-10-CM and ICD-10-PCS in terms of purpose.

• A. ICD-10-CM codes visits; ICD-10-PCS codes medications
• B. ICD-10-CM codes diagnoses for medical conditions; ICD-10-PCS codes procedures for inpatient hospital procedures
• C. ICD-10-CM codes procedures; ICD-10-PCS codes diagnoses
• D. ICD-10-CM codes billing; ICD-10-PCS codes diagnoses

Answer: (B)

The essential idea is that diagnosis coding and procedure coding serve different purposes. ICD-10-CM records the patient’s medical conditions—what the patient has or is being treated for. ICD-10-PCS records the procedures performed, and it’s used for inpatient hospital procedures. This matters because the diagnosis code explains why care was needed, while the procedure code documents what was actually done during an admission. For example, a pneumonia diagnosis gets an ICD-10-CM code, and any surgical or other procedural act performed during that hospital stay gets an ICD-10-PCS code. Note that outpatient procedures and professional services typically use CPT/HCPCS codes rather than ICD-10-PCS.