What type of coding system combines both diagnosis and procedure codes?

The combination of diagnosis and procedure codes is characteristic of the ICD-10-PCS, making it the relevant choice. This system is specifically designed for hospital inpatient settings and includes a comprehensive list of procedure codes that correspond with the diagnoses outlined in ICD-10-CM.

ICD-10-CM is strictly a diagnosis coding system used for outpatient settings and does not include procedure codes. CPT is also focused on procedures and services provided by healthcare professionals but does not encompass diagnosis codes. ICD-O-3 is a specialized classification used for cancer diagnosis and is not intended for procedure coding at all. Therefore, the ICD-10-PCS serves as the appropriate coding system for cases where both diagnosis and procedure information is needed, particularly in an inpatient context.