By using data from the National Longitudinal Study of Adolescent Health, we examine how adolescent relationship characteristics, partner attributes, and sexual relationship histories are associated with contraceptive use and consistency, incorporating random effects to control for respondent-level unobserved heterogeneity. Analyses show that teens' contraceptive use patterns vary across relationships. Teens with more-homogamous partners, with more-intimate relationships, and who communicate about contraception before sex have greater odds of contraceptive use and/or consistency. Teens in romantic relationships, and who are older when engaging in sex for the first time, have greater odds of ever using contraceptives but reduced odds of always using contraceptives. Teens continue habits from previous relationships: teens with experience practicing contraceptive consistency and females who previously have used hormonal contraceptive methods are better able to maintain consistency in subsequent relationships. Also, relationship and partner characteristics are less important for females who previously used hormonal methods.