ICD-10 Code M04.8 – Other autoinflammatory syndromes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code M04.8 – Other autoinflammatory syndromes
What it is
M04.8 identifies autoinflammatory syndromes that do not fit a more specific ICD-10-CM category. These conditions involve recurrent, innate immune-driven inflammation rather than classic autoimmune disease.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include recurrent fever, inflammation, rash, joint pain, or other episodic inflammatory symptoms without a clear infectious cause.
When to use this code
Use M04.8 when the provider documents an autoinflammatory syndrome and no more specific code is available. It is appropriate for confirmed syndromes that are described as “other” or otherwise unclassified in the record. Check documentation if the diagnosis is only suspected.
Do not use for
Do not use this code for autoimmune disorders, infectious fever, or a more specific autoinflammatory diagnosis that is documented elsewhere. If the record names a distinct syndrome, code that condition instead.
Coding tip
Code M04.8 only when the provider clearly links the condition to an autoinflammatory syndrome and no specific alternative code applies.