OBJECTIVE: To promote the use of long-acting reversible contraceptive (LARC) methods (intrauterine devices [IUDs] and implants) and provide contraception at no cost to a large cohort of participants in an effort to reduce unintended pregnancies in our region. METHODS: We enrolled 9,256 adolescents and women at risk for unintended pregnancy into the Contraceptive CHOICE Project, a prospective cohort study of adolescents and women desiring reversible contraceptive methods. Participants were recruited from the two abortion facilities in the St. Louis region and through provider referral, advertisements, and word of mouth. Contraceptive counseling included all reversible methods but emphasized the superior effectiveness of LARC methods (IUDs and implants). All participants received the reversible contraceptive method of their choice at no cost. We analyzed abortion rates, the percentage of abortions that were repeat abortions, and teenage births. RESULTS: We observed a significant reduction in the percentage of abortions that were repeat abortions in the St. Louis region compared with Kansas City and nonmetropolitan Missouri (P<.001). Abortion rates in the CHOICE cohort were less than half the regional and national rates (P<.001). The rate of teenage birth within the CHOICE cohort was 6.3 per 1,000, compared with the U.S. rate of 34.3 per 1,000. CONCLUSION: We noted a clinically and statistically significant reduction in abortion rates, repeat abortions, and teenage birth rates. Unintended pregnancies may be reduced by providing no-cost contraception and promoting the most effective contraceptive methods.