ICD-10-CM categories consist of how many characters?

In the ICD-10-CM coding system, categories consist of three characters. The first character is always an alphabetic letter, followed by two numeric characters. This structure allows for a wide classification of diseases and conditions, enabling precise coding essential for billing, statistical, and healthcare management purposes. Having a standardized three-character category ensures that there is a uniform understanding of diagnoses across various healthcare settings, aiding in data collection and analysis.

The options with one, four, or five characters do not align with the established coding structure of the ICD-10-CM categories. Categories are specifically designed to maintain a balance between simplicity and detailed classification, and the three-character setup achieves that effectively.