Section I.C of the ICD-10-CM Official Guidelines for Coding and Reporting, titled “Chapter Specific Guidelines,” contains 22 chapters. These chapters offer detailed guidance on specific codes and code ranges in the ICD-10-CM manual. This article is part of a series that will delve into each of the chapters in Section I.C to delineate coding protocols and rules for each section.

While the importance of understanding the General Coding Guidelines of Section I.B cannot be understated if you are to become a successful medical coder, you must also incorporate the rules that were created for each specific chapter into your coding process. These guidelines can seem confusing at times, but they must be followed. If in doubt, reach out to your Medicare administrative contractors (MACs) for clarification.

• Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00-E89)
• Chapter 5: Mental, Behavioral and Neurodevelopmental disorders (F01 – F99)
• Chapter 6: Diseases of the Nervous System (G00-G99)