Vaccination guidelines for recipients of blood and marrow transplantation (BMT) have been published by 3 major societies: American Blood and Marrow Transplantation, European Group of Blood and Marrow Transplantation, and Infectious Disease Society of America. Despite these extensive review articles, clinicians caring for BMT recipients continue to field frequently asked questions (FAQs) regarding the “who, when, and how” of feasible and effective posttransplant vaccination, frequently in the absence of adequate data. This may reflect discomfort with a “one size fits all” policy that makes no adjustments for different posttransplant clinical scenarios. Existing guidelines also lack practical dose clarifications when administering vaccines to patients who differ by age, underlying diagnosis, or amount of immunosuppressive therapy. Frequently, little or conflicting guidance is given regarding age-related schedules for certain vaccines (eg, meningococcal; tetanus toxoid, reduced diphtheria toxoid, and reduced acellular pertussis; and human papillomavirus vaccines) in addition to time posttransplant or other factors. FAQs and their answers form the body of this article and are shared with readers as a concise practical review, with the intent to facilitate good clinical practice.