Background. Social media (SM) use has been positively associated with disturbed sleep among young adults. However, previous studies have not elucidated the specific importance of SM use immediately before bed. We aimed to determine the independent association of SM use during the 30 minutes before bed and disturbed sleep while controlling for covariates including total SM use throughout the day. Methods. We assessed a nationally-representative sample of 1763 U.S. young adults ages 19-32. Participants estimated to what extent they used SM in the 30 minutes before bed. We assessed sleep disturbance using the brief Patient-Reported Outcomes Measurement Information System (PROMIS®) Sleep Disturbance measure. After testing the proportional odds assumption, we used ordered logistic regression to compute the independent association between SM use before bed and sleep disturbance controlling for covariates, including total SM use. Results. Compared with those who rarely or very rarely check SM in the 30 minutes before bed, those who often or very often check SM at that time had an AOR of 1.62 (95% CI=1.31-2.34) for increased sleep disturbance. Additionally, we found a significant linear association between the frequency of checking SM in the 30 minutes before bed and increased sleep disturbance (p=0.007). Results were consistent in all sensitivity analyses. Conclusions. SM use in the 30 minutes before bed is independently associated with disturbed sleep among young adults. Future work should use qualitative and experimental methods to further elucidate the directionality of—and mechanisms underlying—this association.