Which coding system is primarily used for hospital inpatient services?

The International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) is primarily used for hospital inpatient services as it provides standardized codes for diagnoses and conditions treated during inpatient stays. This coding system is essential for accurately documenting patient conditions and is used by healthcare providers to ensure appropriate reimbursement from insurers for services rendered.

ICD-10-CM codes allow hospitals and healthcare facilities to categorize patient diagnoses to facilitate billing and coding for inpatient care, influencing reimbursement rates through various payment systems, such as the Inpatient Prospective Payment System (IPPS).

In contrast, Current Procedural Terminology (CPT) is primarily used for outpatient services and procedures rather than diagnoses. The Healthcare Common Procedure Coding System (HCPCS) encompasses codes for certain procedures and services, including outpatient settings and specific supplies but is not primarily focused on inpatient stays. Lastly, Diagnosis Related Group (DRG) refers to a classification system for reimbursement based on the diagnosis of patients but does not function as a coding system itself. DRGs utilize the ICD-10-CM codes among others to determine payment categories but are not the coding system used to classify diagnoses.