Family practice became the 20th U.S. medical specialty in 1969. It has delivered on its promise to reverse the decline of general practice and care for people with diverse problems in all areas of the country. But many important health care problems remain unsolved, in part because of poor role delineation for family physicians, poor differentiation of family practice from other fields, and insufficient changes in the cultural and political environment. Family practice's problems include confusion about whether it is a reform movement or an incumbent specialty; disagreement about its role in controlling and assuring care; confusion about whether family physicians are generalists or specialists; lack of clarity about family practice as vital for all versus a possible option for some; misunderstanding about the knowledge requirements for family practice; and inadequate business models. Family practice's mistakes include expending much effort on justification and less on assuring practical means to accomplish its work; permitting an erosion of public trust; failing to strengthen relationships with interfacing specialties and organizations; and neglecting research. Nonetheless, there are promising opportunities to improve health and health care through strengthening family practice that depend in part on redesigning the family practice setting, defining carefully critical interactions with other elements of the health care system, fostering discovery of family practice, and further differentiating family practice as a scientific and caring field. Another period of adaptation by family practice is already under way; this may be the first time in history that its ambitious aspirations are actually achievable.