OBJECTIVE The purpose of this study was to determine predictors of the completion of free annual sexually transmitted infection screening among sexually active young women of ≤ 25 years old. METHODS We analyzed survey data from 2607 sexually active women who were enrolled in the Contraceptive CHOICE Project, a prospective cohort study. We evaluated demographic characteristics, sexual risk behaviors, relationship characteristics, and contraceptive methods. Receipt of a home- or clinic-based test kit within 56 days of the 12-month survey constituted a completed screen. A multivariable model to predict screening completion was created with the use of Poisson regression with robust error variance. RESULTS Fifty-seven percent of the women completed the screening. Screening completion was associated most strongly with a college education or higher (adjusted relative risk, 1.2; 95% confidence interval, 1.1-1.3) and home-based testing (adjusted relative risk, 1.3; 95% confidence interval, 1.2-1.5). CONCLUSIONS Free and home-based testing increased screening rates among young women. To meet annual testing guidelines, the availability and use of home-based testing kits should increase.