Medical education in the USA today is remarkably varied despite the shared mission of training doctors, hardly surprising given that there are today 125 medical schools in the United States. In this paper, a brief introduction to six of those institutions--describing how they and their mandates differ--illustrates some of the variety of US medical education currently available, while providing some specific details of just how those six schools differ from each other. These are only samples, of course; the variety is far greater than can be made clear in such a short review. Three private institutions are included: Dartmouth Medical School (the nation's fourth-oldest medical school), Duke University School of Medicine (a 20th-century creation, in the South), and Mount Sinai School of Medicine (a newcomer in the crowded medical world of New York City). Three state-supported schools are also described: the University of Arizona College of Medicine (one of the nation's newer schools), Oregon Health & Science University School of Medicine (an institution that has gone through many permutations, thanks to a variety of mergers), and Southern Illinois University School of Medicine (another new school that has focused on serving its immediate locale while creating a national model for some kinds of student assessment). General remarks are made about changes over recent years in three separate areas of influence. One is the fact that forty new medical schools were established between 1960 and 1980; a short explanation is provided of the reasons for this and how this mammoth task was achieved. Secondly, a few of the numerous innovative programs and new emphases that have become part of the medical school curriculum in one institution or another are discussed briefly. And then, thirdly, a small sample is given of ways in which a few other particular medical schools have reformed their curricula in recent years; what went into the most influential of these curricular reforms is also presented, along with mention of what are perhaps the most unusual curricular paths today. The paper concludes with a summary assessment of where reforms in the second half of the 20th century have brought US medical education at the beginning of the 21st century as well as a sobering comment on the extent to which much remains to be accomplished in the delivery of health care in the United States despite the improvements in medical education. These observations constitute an important feature of the paper, because although much has previously been written on the history of medical education in the USA that provides a general picture of how physicians are trained there and contributes to an understanding of changes in that training, this article adds specificity to the general picture and makes absolutely clear that an astonishing degree of diversity exists in US medical education.