Newborn screening tests are designed to detect infants with specific conditions whose families also benefit from early diagnosis and treatment. These conditions include disorders of metabolism, endocrinopathies, hemoglobinopathies, hearing loss, and cystic fibrosis. Each state program must have a system in place for notification, timely follow-up, and evaluation of any infant with a positive screening result. Newborn screening programs have enormous public health benefits and have been effective in identifying newborns that can benefit from early treatment.