How many digits do subcategories in ICD-10-CM typically contain?

In ICD-10-CM, subcategories typically contain four to six characters. The structure of the coding system starts with a letter followed by a series of digits, which usually includes a combination of these four to six characters to provide a detailed description of the diagnosis.

Subcategories help to specify the diagnosis further by indicating variations or specificity, such as laterality or specific conditions. The fact that this option correctly describes the range of characters in subcategories reflects how these codes are designed to be more detailed compared to broader categories, which may require only three characters. Thus, the correct answer emphasizes the organized and structured approach of ICD-10-CM in categorizing medical diagnoses.