Immunizations are a critical feature of preventative care for term and preterm newborns. All infants, regardless of gestational age, should receive hepatitis B vaccine shortly after delivery. For preterm infants who remain in the neonatal intensive care unit, providers may be tasked with administering their 2-, 4-, 6-, or even 12-month vaccines. Ensuring that these immunizations are given promptly will prevent under-immunization at the time of nursery discharge. In addition, preterm infants may be eligible for one or both of influenza vaccination or palivizumab administration depending on risk factors and the time of year. Infants who reach 6 months of age during their nursery course are also eligible for vaccination against COVID-19. The appropriate timing and indications for these immunizations for term and preterm infants are described in this chapter.