Infectious and Parasitic Diseases, Systemic or Unspecified Sites

MDC18 groups inpatient cases whose principal diagnosis is an infectious or parasitic disease that involves the whole body or an unspecified site, such as sepsis, bacteremia, systemic fungal infections, or viral illnesses without a localized focus. It is used in the FY2024 Medicare Severity Diagnosis Related Groups system to assign payment rates for these broadly systemic infections.