OBJECTIVES: (1) To describe contemporary birth centers in terms of the population served, organizational and financial characteristics, services provided, mission and philosophy, and planning and marketing techniques. (2) To compare hospital-sponsored and nonhospital models with regard to the above characteristics. METHOD: Data from the National Survey of Women's Health Centers conducted in 1994 are analyzed using t-tests and chi-square tests. RESULTS: Contemporary birth centers serve a diverse population of women and provide a range of clinical and nonclinical services. Birth centers are both hospital-sponsored and nonhospital, with the former growing at a faster rate. Compared to hospital-sponsored centers, nonhospital centers serve a larger proportion of uninsured women, provide a broader range of clinical services, and are more committed to women-centered care. Centers utilize different marketing methods and are involved in a number of organizational changes to better position themselves in the changing health care environment. CONCLUSIONS: Birth centers offer an attractive option to consumers and are a viable model for delivering women-centered care. Given that all "birth center" facilities do not share the same philosophy and service mix, women need to have some assurance of what a "birth center" will, and will not, provide.