What are the coding differences between outpatient and inpatient settings for diagnosis and procedures?

• A. Outpatient uses ICD-10-CM and CPT/HCPCS; inpatient uses ICD-10-CM diagnoses and ICD-10-PCS procedures with DRG reimbursement
• B. Both use ICD-10-CM and CPT for procedures
• C. Outpatient uses ICD-9-CM; inpatient uses ICD-10-CM
• D. There is no difference in coding between settings

Answer: (A)

The key distinction in coding between outpatient and inpatient settings lies in the procedure coding system and the reimbursement method. In outpatient care, diagnoses are coded with ICD-10-CM and procedures are coded with CPT or HCPCS, reflecting the itemized services billed to payers for ambulatory encounters. In inpatient care, diagnoses still use ICD-10-CM, but procedures are coded with ICD-10-PCS, a separate system created specifically for hospital inpatient procedures. Reimbursement patterns also differ: inpatient stays are typically paid using Diagnosis-Related Groups (DRGs), which bundle payment based on the diagnosis and procedures, whereas outpatient claims are paid based on CPT/HCPCS-coded services. So the statement that outpatient uses ICD-10-CM and CPT/HCPCS and inpatient uses ICD-10-CM diagnoses and ICD-10-PCS procedures with DRG reimbursement accurately captures these differences. The other options are not correct because they either ignore the ICD-10-PCS system, reference outdated ICD versions, or claim there’s no difference in coding.