MS-DRG v36 (FY 2019) Definitions Manual - Browse Assignment Rules and Codes

CMS (Centers for Medicare & Medicaid Services) created the MS-DRG system as a way to classify each Medicare patient's hospital stay into a severity group. These severity groups help to determine how much a hospital is paid for treating the patient based on the expected cost and complexity of the treatment.

Each year, CMS updates the MS-DRGs to reflect current trends in treatment and to reflect any changes in how patients are being treated. Use the MS-DRG Versions menu above to choose the year you would like to see.

Major Diagnostic Categories (MDCs)

MS-DRGs are divided into Major Diagnostic Categories (MDCs) that represent each area of treatment. The order of MDCs reflects their relative importance. If a patient receives treatment in multiple MDCs, the first one listed below takes precedence. Pre-MDC contains treatments that are considered so complex that they take priority over any specific area of treatment.

MDC Description
Pre Pre-MDC
MDC 01 Diseases & Disorders of the Nervous System
MDC 02 Diseases & Disorders of the Eye
MDC 03 Diseases & Disorders of the Ear, Nose, Mouth & Throat
MDC 04 Diseases & Disorders of the Respiratory System
MDC 05 Diseases & Disorders of the Circulatory System
MDC 06 Diseases & Disorders of the Digestive System
MDC 07 Diseases & Disorders of the Hepatobiliary System & Pancreas
MDC 08 Diseases & Disorders of the Musculoskeletal System & Connective Tissue
MDC 09 Diseases & Disorders of the Skin, Subcutaneous Tissue & Breast
MDC 10 Endocrine, Nutritional & Metabolic Diseases & Disorders
MDC 11 Diseases & Disorders of the Kidney & Urinary Tract
MDC 12 Diseases & Disorders of the Male Reproductive System
MDC 13 Diseases & Disorders of the Female Reproductive System
MDC 14 Pregnancy, Childbirth & the Puerperium
MDC 15 Newborns & Other Neonates with Conditions Originating in Perinatal Period
MDC 16 Diseases & Disorders of Blood, Blood Forming Organs, Immunologic Disorders
MDC 17 Myeloproliferative Diseases & Disorders, Poorly Differentiated Neoplasms
MDC 18 Infectious & Parasitic Diseases, Systemic or Unspecified Sites
MDC 19 Mental Diseases & Disorders
MDC 20 Alcohol/Drug Use & Alcohol/Drug Induced Organic Mental Disorders
MDC 21 Injuries, Poisonings & Toxic Effects of Drugs
MDC 22 Burns
MDC 23 Factors Influencing Health Status & Other Contacts with Health Services
MDC 24 Multiple Significant Trauma
MDC 25 Human Immunodeficiency Virus Infections
MDC XX Unrelated Operating Room Procedures
Appendix A - List of MS-DRGs

Quick Actions