ICD-10-CM 2027 diagnosis code
G44Other headache syndromes
G44 is a header code, so it can't be reported by itself. Choose one of the 7 more specific codes beneath it.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About G44
G44 is the ICD-10-CM diagnosis code for other headache syndromes. It belongs to block G40-G47 (episodic and paroxysmal disorders) and chapter 6 (diseases of the nervous system). It is a header code, so it can't be reported by itself; one of its 7 subcodes must be used instead.
To report this condition, pick the subcode that matches the documentation: G44.0 ((TAC)), G44.1 (classified), G44.2 (headache), G44.3 (headache), G44.4 (classified), G44.5 (syndromes) and G44.8 (syndromes).
Don't report G44 together with the conditions in its Excludes1 note: headache NOS (R51.9).
The conditions in its Excludes2 note aren't part of G44, but may be coded alongside it if the patient has both: atypical facial pain (G50.1), headache due to lumbar puncture (G97.1), migraines (G43.-) and trigeminal neuralgia (G50.0).
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Specific codes under G44
- G44.0Cluster headaches and other trigeminal autonomic cephalgias (TAC)
- G44.00Cluster headache syndrome, unspecified
- G44.01Episodic cluster headache
- G44.02Chronic cluster headache
- G44.03Episodic paroxysmal hemicrania
- G44.04Chronic paroxysmal hemicrania
- G44.05Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT)
- G44.09Other trigeminal autonomic cephalgias (TAC)
- G44.1Vascular headache, not elsewhere classifiedBillable
- G44.2Tension-type headache
- G44.3Post-traumatic headache
- G44.4Drug-induced headache, not elsewhere classified
- G44.5Complicated headache syndromes
- G44.8Other specified headache syndromes
Coding notes
Notes that apply from higher levels
Instructions written at a parent level also apply to G44.
Broader instructions also apply from Chapter 6: Diseases of the nervous system.
Codes whose notes reference G44
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about G44
Is G44 billable?
- No. G44 is a header code. Report one of its more specific subcodes instead.