How many characters can ICD-10-CM codes have at maximum?

ICD-10-CM codes can have a maximum of seven characters. Each code begins with a letter followed by a series of alphanumeric characters, which can include up to six additional characters for further specificity. The structure of these codes allows for a comprehensive classification of diagnoses, conditions, and external causes of injury or diseases.

The prefix character helps identify the chapter of the classification system, and the additional characters provide detail regarding etiology, anatomic site, severity, and other clinical details necessary for accurate coding and billing processes. The seven-character format allows healthcare providers to capture a wide array of clinical data, which is crucial for research, statistics, and healthcare services management.

In contrast, five, nine, and three characters do not align with the standard coding format established for ICD-10-CM, which confirms that the correct maximum for these codes is indeed seven characters.