Perinatal hepatitis B (HepB) infection is a serious condition in the pediatric population, with up to 90% of exposed infants progressing to chronic infection. The cornerstone of prevention is the birth dose of the HepB vaccine. In 2018, the Advisory Committee on Immunization Practices updated their guidelines for the birth dose of the HepB vaccine. These new guidelines included a refined timeline on when the HepB vaccine should be given, including for infants born to women with known HepB infection, unknown HepB status, and universal guidelines regardless of maternal HepB status. However, despite these guidelines, up to 25% of infants do not receive the birth dose of HepB vaccine. Individual provider commitment to administration of the vaccine remains fundamental, but institutional policies also have significant influence in ensuring appropriate vaccine administration for infants. [Pediatr Ann. 2021;50(8):e343-e347.].