Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a lifesaving therapy increasingly used to treat a range of conditions in adults and children, including leukemia, lymphoma, and some solid cancers. The development of this therapy has significantly increased survival rates from what were once terminal conditions. Despite these advances, survivors experience a range of long-term and late effects of therapy necessitating lifelong monitoring. Allo-HSCT survivors are at an increased risk for secondary cancers, infections (including vaccine-preventable diseases), graft-versus-host disease (GVHD), and chronic illnesses which impact all body systems. These conditions result in compromised functional status, unemployment and underemployment, and decreased quality of life. Allo-HSCT survivors report twice as many (mostly preventable) medical problems compared to case-matched controls and are 3.5 times more likely to develop a severe/life-threatening condition than siblings (this increases up to 4.7 times in those with GVHD and higher rates of hospitalizations). Accordingly, international and national consensus guidelines recommend the long-term follow-up assessments, health counseling, preventive care, vaccinations, and cancer screening to optimize the benefit and minimize the late effects of allo-HSCT. This chapter provides an overview of the impacts of allo-HSCT on survivors before outlining the 2023 updated international recommendations for screening and preventative practices for long-term survivors of Transplantation and Cellular Therapy.