The practice of obstetrics and gynecology continues to evolve. Changes in the obstetrician-gynecologists workforce, reimbursement, governmental regulations, and technology all drive new models of care. The advent of the obstetric hospitalist is one new model, and the development of team-based care is another. Increasingly, obstetrician-gynecologists are becoming employees of health care delivery systems, and others are focusing the scope of their practices to subspecialites. As new practice models emerge, the specialty of obstetrics and gynecology will continue to change to meet the health care needs of women.