Fertility awareness-based methods (FABMs) are a group of family planning methods that allow users to track one or more biomarkers to determine the days during each menstrual cycle when the chances of conception would be highest and lowest. Users of FABMs who want to avoid pregnancy avoid unprotected intercourse during the Fertile Window. Modern FABMs use one or more biomarkers to predict the Fertile Window including menstrual cycle dates, cervical mucus, basal body temperature, and/or urinary hormones. Each FABM has unique user considerations and effectiveness estimates. Typical use effectiveness estimates range from 2 to 33 pregnancies per 100 women years. Effectiveness for users with long or irregular cycles is understudied. Misinformation about these methods persists due in part to lack of health care provider knowledge and experience with counseling about these methods. People who desire to use FABMs deserve transparent information from their health care providers about use and effectiveness so that they can choose a method that is best for them.