This is the CodeSystem that contains codes in both Medicare Severity Diagnosis Related Groups (MS-DRGs) (https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/AcuteInpatientPPS/MS-DRG-Classifications-and-Software) and Medicare Severity Diagnosis Related Groups (MS-DRGs) (https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/AcuteInpatientPPS/MS-DRG-Classifications-and-Software).