click on single ICD9 identifiers to add to search input box, click on description to enter next level.
001-1391. INFECTIOUS AND PARASITIC DISEASES (001-139)
140-2392. NEOPLASMS (140-239)
240-2793. ENDOCRINE, NUTRITIONAL AND METABOLIC DISEASES, AND IMMUNITY DISORDERS (240-279)
280-2894. DISEASES OF THE BLOOD AND BLOOD-FORMING ORGANS (280-289)
290-3195. MENTAL, BEHAVIORAL AND NEURODEVELOPMENTAL DISORDERS (290-319)
320-3896. DISEASES OF THE NERVOUS SYSTEM AND SENSE ORGANS (320-389)
390-4597. DISEASES OF THE CIRCULATORY SYSTEM (390-459)
460-5198. DISEASES OF THE RESPIRATORY SYSTEM (460-519)
520-5799. DISEASES OF THE DIGESTIVE SYSTEM (520-579)
580-62910. DISEASES OF THE GENITOURINARY SYSTEM (580-629)
630-67911. COMPLICATIONS OF PREGNANCY, CHILDBIRTH, AND THE PUERPERIUM (630-679)
680-70912. DISEASES OF THE SKIN AND SUBCUTANEOUS TISSUE (680-709)
710-73913. DISEASES OF THE MUSCULOSKELETAL SYSTEM AND CONNECTIVE TISSUE (710-739)
740-75914. CONGENITAL ANOMALIES (740-759)
760-77915. CERTAIN CONDITIONS ORIGINATING IN THE PERINATAL PERIOD (760-779)
780-79916. SYMPTOMS, SIGNS, AND ILL-DEFINED CONDITIONS (780-799)
800-99917. INJURY AND POISONING (800-999)