F99 is not a valid ICD-10-CM billing code

F99 exists in the World Health Organization's base ICD-10 classification, but was never adopted into ICD-10-CM (the United States clinical modification used for medical billing). It cannot be used on a US claim.

MedCoder.ai does not reproduce WHO's classification. Read the entry in WHO's own ICD-10 browser: F99 at icd.who.int