ICD-10-CM > G00-G99 > G40-G47 > G44 > G44.0 > G44.09 G44.09 Other trigeminal autonomic cephalgias (TAC) Non-Billable/Non-Specific Codes G44.091Other trigeminal autonomic cephalgias (TAC), intractableG44.099Other trigeminal autonomic cephalgias (TAC), not intractable