Which coding system is primarily used for outpatient services?

The correct choice is CPT, which stands for Current Procedural Terminology. This coding system is specifically designed to describe the medical, surgical, and diagnostic services and procedures performed by healthcare providers, primarily in outpatient settings. CPT codes are used widely for billing purposes to communicate the services rendered to patients and to ensure correct reimbursement from insurance companies.

CPT codes are structured to provide detailed descriptions of various procedures, which is crucial in outpatient care where a variety of services can be rendered in a single visit. While ICD-10 codes are used for diagnosing conditions, and HCPCS is utilized for other services and supplies that aren’t covered in CPT, CPT is the primary system for reporting outpatient procedures. DRG, or Diagnosis-Related Group, is a classification system primarily used for inpatient hospital stays and is not applicable to outpatient services.