In the United States during 1994, approximately 49% of all pregnancies, excluding miscarriages, were unintended. Unintended pregnancy can result in adverse health outcomes that affect the mother, infant, and family. Little is known about the distribution of unintended pregnancy with respect to the payment source for health care. In the absence of data for periconceptional payment source for health care, prenatal-care payment source is used as a surrogate. To develop recommendations to reduce unintended pregnancy, CDC analyzed insurance coverage-specific prevalences of live-born infants from unintended pregnancies among women aged 20-34 years using data from the Pregnancy Risk Assessment and Monitoring System (PRAMS) for 1996 (the most recent year for which data are available). This report summarizes the results of this analysis, which indicates that the highest rates of unintended pregnancy occurred among women covered by Medicaid, with lower rates among women covered by health-maintenance organizations (HMOs) or private insurance.