During an interval of 15 years, the Lucille P. Markey Charitable Trust spent over $500 million on four programs in the basic biomedical sciences that support the education and research of graduate students, postdoctoral fellows, junior faculty, and senior researchers. The Markey Trust asked the NRC to evaluate these programs with two questions in mind: "Were these funds well spent?" and "What can others in the biomedical and philanthropic communities learn from the programs of the Markey Trust, both as an approach to funding biomedical research and as a model of philanthropy?" One of five resulting reports, this volumeexamines the Research Program Grants, which awarded $323 million to support investigators with a major commitment to the life sciences and to assist in the establishment, reorganization, or expansion of significant biomedical research centers or programs. Using information from Markey archives, materials from grant recipients, and site visits to a sample of institutional grant recipients, the authoring committee describes the impact that Markey grants made on the centers and programs funded by these grants, along with the unique aspects of the Markey approach to funding that may be applicable to other funders of biomedical research programs.