Fanconi Anemia (FA) is characterized by fragile bone marrow and the inability to repair DNA damage which accumulates in repopulating stem cells, leading to marrow failure. Current treatments often involve bone marrow transplantation however the majority of patients will not have an appropriately matched sibling donor and transplants from alternative donors are still associated with substantial toxicity and morbidity. Alternatively, new gene therapy approaches are being tested in the clinic which aim to introduce a corrected form of the mutated gene through collection and modification of the patients own stem cells in a sterile tissue culture facility. While this method has shown early potential, there remains significant risk for additional DNA damage to occur while the cells are cultured outside the body. Using mouse models, this study aims to develop and optimize protocols for administering this gene therapy treatment in vivo through IV injection to correct hematopoietic stem cells and reverse marrow failure seen in FA patients.