The Major Diagnostic Categories (MDC) are formed by dividing all possible principal diagnoses (from ICD-9-CM) into 25 mutually exclusive diagnosis areas. MDC codes, like diagnosis-related group (DRG) codes, are primarily a claims and administrative data element unique to the United States medical care reimbursement system. DRG codes also are mapped, or grouped, into MDC codes.
The diagnoses in each MDC correspond to a single organ system or cause and, in general, are associated with a particular medical specialty. MDC 1 to MDC 23 are grouped according to principal diagnoses. Patients are assigned to MDC 24 (Multiple Significant Trauma) with at least two significant trauma diagnosis codes (either as principal or secondaries) from different body site categories. Patients assigned to MDC 25 (HIV Infections) must have a principal diagnosis of an HIV Infection or a principal diagnosis of a significant HIV related condition and a secondary diagnosis of an HIV Infection.
MDC 0, unlike the others, can be reached from a number of diagnosis/procedure situations, all related to transplants. This is due to the expense involved for the transplants so designated and because these transplants can be needed for a number of reasons which do not all come from one diagnosis domain. DRGs which reach MDC 0 are assigned to the MDC for the principal diagnosis instead of to the MDC associated with the designated DRG.
List of Major Diagnostic Categories
MDCDescriptionMS-DRG0Pre-MDC001 - 0171Diseases and Disorders of the Nervous System020 - 1032Diseases and Disorders of the Eye113 - 1253Diseases and Disorders of the Ear, Nose, Mouth And Throat129 - 1594Diseases and Disorders of the Respiratory System163 - 2085Diseases and Disorders of the Circulatory System215 - 3166Diseases and Disorders of the Digestive System326 - 3957Diseases and Disorders of the Hepatobiliary System And Pancreas405 - 4468Diseases and Disorders of the Musculoskeletal System And Connective Tissue453 - 5669Diseases and Disorders of the Skin, Subcutaneous Tissue And Breast573 - 60710Diseases and Disorders of the Endocrine, Nutritional And Metabolic System614 - 64511Diseases and Disorders of the Kidney And Urinary Tract652 - 70012Diseases and Disorders of the Male Reproductive System707 - 73013Diseases and Disorders of the Female Reproductive System734 - 76114Pregnancy, Childbirth And Puerperium765 - 78215Newborn And Other Neonates (Perinatal Period)789 - 79516Diseases and Disorders of the Blood and Blood Forming Organs and Immunological Disorders799 - 81617Myeloproliferative DDs (Poorly Differentiated Neoplasms)820 - 84918Infectious and Parasitic DDs (Systemic or unspecified sites)853 - 87219Mental Diseases and Disorders876 - 88720Alcohol/Drug Use or Induced Mental Disorders894 - 89721Injuries, Poison And Toxic Effect of Drugs901 - 92322Burns927 - 93523Factors Influencing Health Status and Other Contacts with Health Services939 - 95124Multiple Significant Trauma955 - 96525Human Immunodeficiency Virus Infection969 - 977MDC Category Missing981 - 989; 998,999
See also Diagnosis-related group Diagnosis code Medical classification
References
External links Utah Department of Health - description of MDC