For the estimated 35 million people in the United States who experience migraines, multiple prescription therapies are available that have proved effective in acutely treating migraine pain and its associated symptoms. Among approved prescription medications, the migraine-specific triptan drug class represents the largest—and most extensively prescribed—group of therapies. All of the molecules in this class are available as oral tablet formulations, and several are also available in non-oral formulations (e.g., nasal sprays, subcutaneous [SC] injectables), which serve as alternative treatment options for patients with precise clinical needs. The branded triptans will continue to have extensive competition from the launch of generics but the triptan class will likely remain as the preferred drug class for use in the acute treatment of migraine. Additional therapies, including ergotamine derivatives and select non-migraine-specific analgesics, represent the remaining therapies that are formally approved for the acute treatment of migraine. Agents from these last two classes are generally reserved for patients who do not respond satisfactorily, cannot tolerate, or, in the case of non-migraine-specific analgesics, are contraindicated to triptans. Using patient-level claims data, this report tracks the share of acute, prescription antimigraine drugs through lines of therapy, evaluates treatment flow, and analyzes why certain key acute therapies are chosen over others in light of the multiple acute therapeutics that are available.