OBJECTIVES: Two MenB vaccines are licensed in the US since 2015: MenB-FHbp and MenB-4C, with a category B recommendation for vaccination at ages 16-23. Both vaccines were approved based on immune responses after series completion, but different dosing schedules and recommendations apply: MenB-4C, 2 doses at least 1 month apart; MenB-FHbp: initially 3 doses (at 0, 1-2, and 6 months), now 2 doses 6 months apart. This study evaluated completion and compliance for MenB-4C or MenB-FHbp vaccination (considering both 2- or 3-dose schedules) in individuals aged 16-23. METHODS: This was a retrospective analysis based on claims data from MarketScan Commercial Claims and Encounters through 2/28/2018. The study population included individuals who initiated MenB-4C or MenB-FHbp between 7/1/2015 and 11/30/2016, with continuous health plan enrollment for 6 months prior and 15 months after series initiation. Series completion was defined as individual receipt of the recommended number of doses within the follow-up period, while compliance was based on adherence to recommended dosing schedule for each vaccine. Current recommendations for MenB-FHbp were applied retroactively. RESULTS: