ICD-10 Code for Headache

The ICD-10-CM code for headache is R51.9 — Headache, unspecified. This is the code the Alphabetic Index gives for headache with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).

BillableUnspecified

R51.9 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.

Which headache code should you use?

The Alphabetic Index lists 42 codes under Headache. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.

By type

allergic NEC	G44.89	Other headache syndrome
associated with sexual activity	G44.82	Headache associated with sexual activity
cervicogenic	G44.86	Cervicogenic headache
chronic daily	R51.9	Headache, unspecified
cluster	G44.009	Cluster headache syndrome, unspecified, not intractable
cough	G44.83	Primary cough headache
daily chronic	R51.9	Headache, unspecified
drug-induced NEC	G44.40	Drug-induced headache, not elsewhere classified, not intractable
exertional	G44.84	Primary exertional headache
histamine	G44.009	Cluster headache syndrome, unspecified, not intractable
hypnic	G44.81	Hypnic headache
lumbar puncture	G97.1	Other reaction to spinal and lumbar puncture
medication overuse	G44.40	Drug-induced headache, not elsewhere classified, not intractable
migraine	G43.909	Migraine, unspecified, not intractable, without status migrainosus
nasal septum	R51.9	Headache, unspecified
neuralgiform, short lasting unilateral, with conjunctival injection and tearing	G44.059	Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), not intractable
new daily persistent	G44.52	New daily persistent headache (NDPH)
orgasmic	G44.82	Headache associated with sexual activity
periodic syndromes in adults and children	G43.C0	Periodic headache syndromes in child or adult, not intractable
postspinal puncture	G97.1	Other reaction to spinal and lumbar puncture
post-traumatic	G44.309	Post-traumatic headache, unspecified, not intractable
preorgasmic	G44.82	Headache associated with sexual activity
rebound	G44.40	Drug-induced headache, not elsewhere classified, not intractable
short lasting unilateral neuralgiform, with conjunctival injection and tearing	G44.059	Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), not intractable
specified syndrome NEC	G44.89	Other headache syndrome
spinal and epidural anesthesia - induced	T88.59	Other complications of anesthesia	not billable
spinal fluid loss	G97.1	Other reaction to spinal and lumbar puncture
stabbing	G44.85	Primary stabbing headache
tension	G44.209	Tension-type headache, unspecified, not intractable
thunderclap	G44.53	Primary thunderclap headache
vascular NEC	G44.1	Vascular headache, not elsewhere classified

Headache with

orthostatic component NEC	R51.0	Headache with orthostatic component, not elsewhere classified
positional component NEC	R51.0	Headache with orthostatic component, not elsewhere classified

Headache cluster

chronic	G44.029	Chronic cluster headache, not intractable
episodic	G44.019	Episodic cluster headache, not intractable
intractable	G44.001	Cluster headache syndrome, unspecified, intractable
not intractable	G44.009	Cluster headache syndrome, unspecified, not intractable
chronic › intractable	G44.021	Chronic cluster headache, intractable
chronic › not intractable	G44.029	Chronic cluster headache, not intractable
episodic › intractable	G44.011	Episodic cluster headache, intractable
episodic › not intractable	G44.019	Episodic cluster headache, not intractable

Headache drug-induced NEC

intractable	G44.41	Drug-induced headache, not elsewhere classified, intractable
not intractable	G44.40	Drug-induced headache, not elsewhere classified, not intractable

Headache histamine

intractable	G44.001	Cluster headache syndrome, unspecified, intractable
not intractable	G44.009	Cluster headache syndrome, unspecified, not intractable

Headache medication overuse

intractable	G44.41	Drug-induced headache, not elsewhere classified, intractable
not intractable	G44.40	Drug-induced headache, not elsewhere classified, not intractable

Headache neuralgiform, short lasting unilateral, with conjunctival injection and tearing

intractable	G44.051	Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), intractable
not intractable	G44.059	Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), not intractable

Headache periodic syndromes in adults and children

with refractory migraine	G43.C1	Periodic headache syndromes in child or adult, intractable
intractable	G43.C1	Periodic headache syndromes in child or adult, intractable
not intractable	G43.C0	Periodic headache syndromes in child or adult, not intractable
without refractory migraine	G43.C0	Periodic headache syndromes in child or adult, not intractable

Headache post-traumatic

acute	G44.319	Acute post-traumatic headache, not intractable
chronic	G44.329	Chronic post-traumatic headache, not intractable
intractable	G44.301	Post-traumatic headache, unspecified, intractable
not intractable	G44.309	Post-traumatic headache, unspecified, not intractable
acute › intractable	G44.311	Acute post-traumatic headache, intractable
acute › not intractable	G44.319	Acute post-traumatic headache, not intractable
chronic › intractable	G44.321	Chronic post-traumatic headache, intractable
chronic › not intractable	G44.329	Chronic post-traumatic headache, not intractable

Headache primary

cough	G44.83	Primary cough headache
exertional	G44.84	Primary exertional headache
stabbing	G44.85	Primary stabbing headache
thunderclap	G44.53	Primary thunderclap headache

Headache rebound

intractable	G44.41	Drug-induced headache, not elsewhere classified, intractable
not intractable	G44.40	Drug-induced headache, not elsewhere classified, not intractable

Headache short lasting unilateral neuralgiform, with conjunctival injection and tearing

intractable	G44.051	Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), intractable
not intractable	G44.059	Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), not intractable

Headache spinal and epidural anesthesia - induced

in labor and delivery	O74.5	Spinal and epidural anesthesia-induced headache during labor and delivery
in pregnancy	O29.4	Spinal and epidural anesthesia induced headache during pregnancy	not billable
postpartum, puerperal	O89.4	Spinal and epidural anesthesia-induced headache during the puerperium

Headache tension

chronic	G44.229	Chronic tension-type headache, not intractable
episodic	G44.219	Episodic tension-type headache, not intractable
intractable	G44.201	Tension-type headache, unspecified, intractable
not intractable	G44.209	Tension-type headache, unspecified, not intractable
chronic › intractable	G44.221	Chronic tension-type headache, intractable
chronic › not intractable	G44.229	Chronic tension-type headache, not intractable
episodic › intractable	G44.211	Episodic tension-type headache, intractable
episodic › not intractable	G44.219	Episodic tension-type headache, not intractable

Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources