Excessive screen time among adolescents increases risk for overweight/obesity. Having electronic devices in the adolescent’s bedroom is associated with more screen time. The present study expanded on previous studies by also examining portable personal electronic devices and social media membership as correlates of screen time use and total sedentary time in the school year and summer among diverse low-income adolescents. Adolescents aged 10-17 years were recruited from lower-income areas, and n=150 completed surveys and wore accelerometers in both the school year and summer: 34 African Americans, 23 American Indians, 16 Asian/Pacific Islanders, 39 Latinos, and 38 White/non-Hispanics. Total sedentary time was computed from accelerometers. Recreational screen time was assessed with a 3-item validated scale. Adolescents reported the presence of 6 electronic devices in their bedrooms, ownership of 4 portable devices, and social media membership. General linear modeling was conducted for both time periods, with demographic covariates and interactions with sex and race-ethnicity. More electronic devices in bedrooms were related to more screen time during the school year and summer, and to more total sedentary time in summer. Personal electronics were only related to more screen time in the school year. Social media membership was related to more total sedentary time in summer, but only among African Americans, American Indians, and non-Hispanic Whites. Electronic devices in bedrooms was confirmed as a risk factor for sedentary behavior among low-income adolescents of color. Social media membership and use should be further studied with diverse adolescents.