The purpose of this study is to find out if azacitidine and venetoclax are an effective treatment approach to get rid of or lower measurable residual disease (MRD) in people with acute myeloid leukemia (AML) who have received standard chemotherapy and are planning to have an allogeneic hematopoietic stem cell transplant (HSCT). Allogeneic HSCT, sometimes called a bone marrow transplant, involves receiving healthy blood-forming cells (stem cells) from a donor in order to replace the patient's immune system and lower the chances of the disease returning (relapse).