The Central Association of Obstetricians and Gynecologists is one of the oldest and most prestigious obstetrics and gynecology associations in the country, and was a founding organization of the American College of Obstetrics and Gynecology in 1951. The association is made up of Obstetricians and Gynecologists primarily residing in the core states:

Alabama, Arizona, Arkansas, Colorado, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, Ohio, Oklahoma, South Dakota, Tennessee, Texas, Utah, West Virginia, Wisconsin, and Wyoming.