| Recommended Mapping (based on statistical analysis) |
| Source ICD-9 | Mapping Type | Target ICD-10 |
| 33900 (Diagnosis) - Cluster headache syn NOS (Cluster headache syndrome, unspecified) | Single To Single | G44009 (Diagnosis) - Cluster headache syndrome, unspecified, not intractable |
| CMS/CDC General Equivalence Mappings |
| 33900 (Diagnosis) - Cluster headache syn NOS (Cluster headache syndrome, unspecified) | Single To Single | Alternative #1: G44009 (Diagnosis) - Cluster headache syndrome, unspecified, not intractable |
Single To Single | Alternative #2: G44001 (Diagnosis) - Cluster headache syndrome, unspecified, intractable |