I.C
Chapter-Specific Coding Guidelines
In addition to general coding guidelines, there are guidelines for specific diagnoses and/or conditions in the classification. Unless otherwise indicated, these guidelines apply to all health care settings. Please refer to Section II for guidelines on the selection of principal diagnosis.
In this section
- I.C.1Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99), U07.1, U09.9
- I.C.2Chapter 2: Neoplasms (C00-D49)
- I.C.3Chapter 3: Disease of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
- I.C.4Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00-E89)
- I.C.5Chapter 5: Mental, Behavioral and Neurodevelopmental disorders
- I.C.6Chapter 6: Diseases of the Nervous System (G00-G99)
- I.C.7Chapter 7: Diseases of the Eye and Adnexa (H00-H59)
- I.C.8Chapter 8: Diseases of the Ear and Mastoid Process (H60-H95)
- I.C.9Chapter 9: Diseases of the Circulatory System (I00-I99)
- I.C.10Chapter 10: Diseases of the Respiratory System (J00-J99), U07.0
- I.C.11Chapter 11: Diseases of the Digestive System (K00-K95)
- I.C.12Chapter 12: Diseases of the Skin and Subcutaneous Tissue
- I.C.13Chapter 13: Diseases of the Musculoskeletal System and Connective
- I.C.14Chapter 14: Diseases of Genitourinary System (N00-N99)
- I.C.15Chapter 15: Pregnancy, Childbirth, and the Puerperium
- I.C.16Chapter 16: Certain Conditions Originating in the Perinatal Period
- I.C.17Chapter 17: Congenital malformations, deformations, and chromosomal abnormalities (Q00-QA1)
- I.C.18Chapter 18: Symptoms, signs, and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
- I.C.19Chapter 19: Injury, poisoning, and certain other consequences of external causes (S00-T88)
- I.C.20Chapter 20: External Causes of Morbidity (V00-Y99)
- I.C.21Chapter 21: Factors influencing health status and contact with health services (Z00-Z99)
- I.C.22Chapter 22: Codes for Special Purposes (U00-U85)
ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026 (effective October 1, 2025). Published by CMS and NCHS. Reproduced for reference — always verify against the official CMS release.