Which coding systems are used to report diagnoses and procedures to CMS?

• A. ICD-10-CM for diagnoses and CPT/HCPCS for procedures and services.
• B. DSM-5 for diagnoses and ICD-9-CM for procedures.
• C. SNOMED for diagnoses and LOINC for procedures.
• D. ICD-9-CM for diagnoses and DRG for procedures.

Answer: (A)

Reporting diagnoses and procedures to CMS relies on standardized code sets that separate what’s wrong from what was done. Diagnoses are written with ICD-10-CM codes, which provide detailed descriptions of patient conditions and are the current standard for billing those conditions to CMS. Procedures and services are captured with CPT codes and HCPCS codes; CPT covers physician and outpatient procedures, while HCPCS Level II extends coding to other services, devices, and supplies not fully described by CPT. This pairing is what CMS uses on claims to ensure consistent, billable documentation across providers.

Other systems serve different roles. DSM-5 outlines criteria for mental disorders and isn’t used for Medicare/Medicaid billing. ICD-9-CM is an older version that has been replaced by ICD-10-CM for diagnoses (and ICD-10-PCS for inpatient procedures). SNOMED is a detailed clinical terminology used in electronic health records, not the claim submission coding set, and LOINC is focused on lab tests. DRG is a payment classification method, not a code set for individual diagnoses or procedures. So the combination of ICD-10-CM for diagnoses and CPT/HCPCS for procedures aligns with how CMS handles reporting.