What is the maximum number of ICD codes that can be entered on a CMS-1500 claim form as of February 2012?

• A. 12
• B. 10
• C. 8
• D. 6

Answer: (A)

In February 2012, the diagnosis field on the CMS-1500 claim form (Box 21) could hold up to twelve ICD-9-CM diagnosis codes. The first code is the primary diagnosis, with up to eleven additional diagnoses listed afterward. This limit comes from the form’s design for paper submissions at that time, ensuring the most relevant conditions fit on the claim. If more than twelve diagnoses were needed, providers would prioritize the key codes or submit additional documentation, but the form itself has a maximum of twelve.