ICD-10-CM>R00-R99>R50-R69>R51R51HeadacheNon-Billable/Non-SpecificType 2 Excludesatypical face pain (G50.1)migraine and other headache syndromes (G43-G44)trigeminal neuralgia (G50.0)CodesR51.0Headache with orthostatic component, not elsewhere classifiedR51.9Headache, unspecified