| ICD-10 Code | Description |
| G44.001 | Cluster headache syndrome, unspecified, intractable |
| G44.009 | Cluster headache syndrome, unspecified, not intractable |
| G44.011 | Episodic cluster headache, intractable |
| G44.019 | Episodic cluster headache, not intractable |
| G44.021 | Chronic cluster headache, intractable |
| G44.029 | Chronic cluster headache, not intractable |
| G44.031 | Episodic paroxysmal hemicrania, intractable |
| G44.039 | Episodic paroxysmal hemicrania, not intractable |
| G44.041 | Chronic paroxysmal hemicrania, intractable |
| G44.049 | Chronic paroxysmal hemicrania, not intractable |
| G44.051 | Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), intractable |
| G44.059 | Short lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), not intractable |
| G44.091 | Other trigeminal autonomic cephalgias (TAC), intractable |
| G44.099 | Other trigeminal autonomic cephalgias (TAC), not intractable |
| G44.1 | Vascular headache, not elsewhere classified |
| G44.201 | Tension-type headache, unspecified, intractable |
| G44.209 | Tension-type headache, unspecified, not intractable |
| G44.211 | Episodic tension-type headache, intractable |
| G44.219 | Episodic tension-type headache, not intractable |
| G44.221 | Chronic tension-type headache, intractable |
| G44.229 | Chronic tension-type headache, not intractable |
| G44.301 | Post-traumatic headache, unspecified, intractable |
| G44.309 | Post-traumatic headache, unspecified, not intractable |
| G44.311 | Acute post-traumatic headache, intractable |
| G44.319 | Acute post-traumatic headache, not intractable |
| G44.321 | Chronic post-traumatic headache, intractable |
| G44.329 | Chronic post-traumatic headache, not intractable |
| G44.40 | Drug-induced headache, not elsewhere classified, not intractable |
| G44.41 | Drug-induced headache, not elsewhere classified, intractable |
| G44.51 | Hemicrania continua |
| G44.52 | New daily persistent headache (NDPH) |
| G44.53 | Primary thunderclap headache |
| G44.59 | Other complicated headache syndrome |
| G44.81 | Hypnic headache |
| G44.82 | Headache associated with sexual activity |
| G44.83 | Primary cough headache |
| G44.84 | Primary exertional headache |
| G44.85 | Primary stabbing headache |
| G44.86 | Cervicogenic headache |
| G44.89 | Other headache syndrome |
