ICD-10-CM 2027 diagnosis code
G44.01Episodic cluster headache
G44.01 is a header code, so it can't be reported by itself. Choose one of the 2 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 G44.01
G44.01 is the ICD-10-CM diagnosis code for episodic cluster headache. It belongs to category G44 (other headache syndromes), 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 2 subcodes must be used instead.
Within G44.0 (cluster headaches and other trigeminal autonomic cephalgias (TAC)), G44.01 is specifically for episodic cluster headache. Related codes cover cluster headache syndrome, unspecified (G44.00), chronic cluster headache (G44.02), episodic paroxysmal hemicrania (G44.03), chronic paroxysmal hemicrania (G44.04), short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) (G44.05) and other trigeminal autonomic cephalgias (TAC) (G44.09).
To report this condition, pick the subcode that matches the documentation: G44.011 (intractable) and G44.019 (not intractable).
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 G44.01
Notes that apply from higher levels
Instructions written at a parent level also apply to G44.01.
› From G44 Other headache syndromes
Broader instructions also apply from Chapter 6: Diseases of the nervous system.
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 G44.01
Is G44.01 billable?
- No. G44.01 is a header code. Report one of its more specific subcodes instead.