Migraine is a neurological disease characterized by moderate or severe headache, associated with nausea, vomiting, and/or sensitivity to light and sound. The study will assess the safety and effectiveness of atogepant for the preventive treatment of migraine in Korean adult patients with chronic migraine or episodic migraine under routine clinical practice. Atogepant is an approved drug for preventive treatment of migraine in adults. Approximately 3000 adult participants who are prescribed atogepant by their doctors will be enrolled in this study in Korea. Participants will receive atogepant oral tablets as prescribed by their physician. Participants will be followed for up to week 12. There is expected to be no additional burden for participants in this trial. Participants will attend regular visits during the study at a hospital or clinic according to their routine clinical practice.