Several options for emergency contraception are available in the United States. This article describes each method, including efficacy, mode of action, safety, side effect profile, and availability. The most effective emergency contraceptive is the copper intrauterine device (IUD), followed by ulipristal acetate and levonorgestrel pills. Levonorgestrel is available for sale without restrictions, whereas ulipristal acetate is available with prescription only, and the copper IUD must be inserted by a clinician. Although EC pills have not been shown to reduce pregnancy or abortion rates at the population level, they are an important option for individual women seeking to prevent pregnancy after sex.