G44.4 Drug-induced headache, not elsewhere classifiedNon-billable header with 2 child codes.
G44.40 Drug-induced headache, not elsewhere classified, not intractableG44.41 Drug-induced headache, not elsewhere classified, intractableG44.1 Vascular headache, not elsewhere classified ("drug-induced headache (G44.4-)")G43 Migraine ("headache syndromes (G44.-)")G89 Pain, not elsewhere classified ("headache syndromes (G44.-)")R51 Headache ("migraine and other headache syndromes (G43-G44)")G44.311 Acute post-traumatic headache, intractableG44.319 Acute post-traumatic headache, not intractableG44.32 Chronic post-traumatic headacheG44.321 Chronic post-traumatic headache, intractableG44.329 Chronic post-traumatic headache, not intractableG44.4 Drug-induced headache, not elsewhere classified (this code)G44.40 Drug-induced headache, not elsewhere classified, not intractableG44.41 Drug-induced headache, not elsewhere classified, intractableG44.5 Complicated headache syndromesG44.51 Hemicrania continuaG44.52 New daily persistent headache (NDPH)