The halls at most schools are still empty, but teachers are already preparing for a new year and some new social-media policies.
Charlotte Secondary School, a charter school in Charlotte, North Carolina, is one of many schools banning social media including Facebook, Twitter and Snapchat during school hours.
But other schools are taking the opposite approach. Instead of banning social media, they're embracing it.
Michele Haiken is a middle school English teacher in New York who was tired of traditional book reports. She started a social media discussion group with her class. Students, with parental consent, meet on Twitter.
"To share books and conversation, to interact and collaborate not only in the classroom, but on a global scale," Haiken explains.
Even when social media isn't in the classroom some teachers use it after school for online office hours or homework help, and say they can help expand the positive benefits of the technology.
Experts say social media can sometimes cause "likes anxiety" among teens, based on how many people like or don't like a post.
During a news conference, President Obama revealed that cellphones are banned from the Obama family dinner table, and his comments are striking a chord across the country. NBC's Sheinelle Jones reports, and psychologist Jennifer Hartstein offers tips to help your family strike the right balance.