Prenatal human immunodeficiency virus (HIV) testing and treatment instituted in the 1990s is responsible for a substantial reduction in the number of children diagnosed with AIDS, yet the number of children born with HIV infection remains unacceptably high. To prevent perinatal transmission of HIV, the United States must adopt a goal to test all pregnant women for HIV and to provide optimal treatment for women who test positive and their children. To meet this goal, the United States should adopt a national policy of universal HIV testing with patient notification as a routine component of prenatal care. Adopting this policy will require the establishment of, and resources for, a comprehensive infrastructure. This infrastructure must include education of prenatal care providers, the development and implementation of practice guidelines and the implementation of clinical policies, the development and adoption of performance measures and Medicaid managed care contract language for prenatal HIV testing, efforts to improve coordination of care and access to high-quality HIV treatment, interventions to overcome pregnant women's concerns about HIV testing and treatment, and efforts to increase use of prenatal care, as described above.