Medical education is facing a convergence of challenges that the authors characterize as the four horsemen of the medical education apocalypse: teaching patient shortages, teacher shortages, conflicting systems, and financial problems. Rapidly expanding class sizes and new medical schools are coming online as medical student access to teaching patients is becoming increasingly difficult because of the decreasing length and increasing intensity of hospital stays, concerns about patient safety, patients who are stressed for time, teaching physician shortages and needs for increasing productivity from those who remain, and increasing emphasis on translational research. Further, medical education is facing reductions in funding from all sources, just as it is mounting its first major expansion in 40 years. The authors contend that medical education is on the verge of crisis and that little outside assistance is forthcoming. If medical education is to avoid a catastrophic decline, it will need to take steps to reinvent itself and make optimum use of all available resources. Curriculum materials developed nationally, increased reliance on simulation and standardized patient experiences, and adoption of quality-control methods such as competency-based education are suggested as ways to keep medical education vital in an environment that is increasingly preoccupied with fending off the four horsemen. The authors conclude with a call for a national dialogue about how the medical education community can address the problems represented by the four horsemen, and they offer some potential ways to maintain the vitality of medical education in the face of such overwhelming problems.