ImportanceAlopecia areata (AA) is characterized by hair loss ranging from patches of hair loss to more extensive forms, including alopecia totalis (AT) and alopecia universalis (AU). There is a lack of consensus for treatment. Understanding current practice patterns could help the identification of treatment needs and development of standards of care.ObjectiveTo review treatment patterns for adults with AA in the US between 2015 and 2020.Design, Setting, and ParticipantsThis retrospective cohort study used medicine and pharmacy claims for commercially insured individuals from the IBM MarketScan Research Database to assess adults (≥18 years) newly treated for AA between October 15, 2015, and February 28, 2020. Alopecia areata was identified based on having at least 1 diagnosis of International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code L63.x. Patients were required to have at least 365 days of continuous health plan enrollment before and after the cohort entry date. Patients were required to be free of AA diagnosis codes 365 days before the cohort entry date. Statistical analyses were conducted between 2019 and 2023.Main Outcomes and MeasuresMain outcomes were treatment patterns for all patients with AA and subgroups of (1) patients with AT or AU and (2) those cared for by a dermatologist on the cohort entry date. Longitudinal therapy course during the first year after the diagnosis was also examined.ResultsThe study cohort consisted of 45 483 individuals (mean [SD] age, 43.8 [14.2] years; 29 903 [65.7%] female). During the year of follow-up, 30 217 patients (66.4%) received at least 1 AA treatment. The most common treatments were intralesional (19 014 [41.8%]), topical (18 604 [40.9%]), intramuscular (17 328 [38.1%]), and oral (9378 [20.6%]) corticosteroids. Compared with patients without AT or AU, patients with AT or AU a lower frequency of intralesional steroid (359 [11.1%] vs 18 655 [44.1%], P < .001) and higher frequency of topical corticosteroid (817 [25.4%] vs 17 787 [42.1%], P < .001) use. Almost half of patients (21 489 [47.2%]) received no treatment on the day of diagnosis. By 12 months, 32 659 (71.8%) were not receiving any treatment, making no treatment the largest study group.Conclusions and RelevanceIn this large cohort study of commercially insured individuals, corticosteroids were the most commonly used treatment for adults with AA between 2015 and 2020. At 365 days after diagnosis, more than two-thirds of patients were no longer receiving any AA treatment. Further studies are needed to understand the reasons for the absence of treatment.