G44.86 vs R51.9
G44.86 (Cervicogenic headache) compared with R51.9 (Headache, unspecified), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. G44.86 carries an Excludes1 note covering R51.9: “headache NOS (R51.9)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Yes, when both are documented. R51.9 carries an Excludes2 note covering G44.86: “migraine and other headache syndromes (G43-G44)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| G44.86Cervicogenic headache | R51.9Headache, unspecified | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | G00-G99 — Diseases of the Nervous System (G00-G99) | R00-R99 — Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99) |
| Definition | Cervicogenic headache is a billable ICD-10-CM diagnosis code (G44.86). | Headache, unspecified is a billable ICD-10-CM diagnosis code (R51.9). |
| Includes | — | Facial pain NOS |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources