ICD-10 Code G44.009 – Cluster headache syndrome, unspecified, not intractable (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G44.009 – Cluster headache syndrome, unspecified, not intractable
What it is
This code identifies cluster headache syndrome when the type is not further specified and the headache is not documented as intractable. It is used for a severe primary headache disorder that occurs in clusters, with remission periods in between.
Clinical signs
Typical features include recurrent unilateral head pain, often around the eye or temple, with autonomic signs such as tearing, nasal congestion, or eyelid swelling. Clinical features vary; refer to documentation.
When to use this code
Use G44.009 when the record states cluster headache syndrome but does not name a more specific subtype. Choose it when the provider documents the condition as not intractable and there is no evidence of chronic or refractory disease.
It also fits when the note confirms cluster headache without enough detail for a more specific code. If the documentation is unclear, check documentation before assigning the code.
Do not use for
Do not use this code for migraine, tension-type headache, or other headache disorders. Do not use it if the provider documents intractable cluster headache or a more specific cluster headache subtype.
Coding tip
Look for the exact wording “not intractable” and “unspecified” in the assessment before selecting G44.009.