A year-plus after Yahoo! chief Marissa Mayer made headlines by banning the company’s popular telecommuting policy to boost worker productivity, a recent study proved her right—and wrong. A Gallup State of the American Workplace report found that people who work remotely are more engaged, enthusiastic and committed to their work — but only if they work outside the office 20% of the time or less. Mayer’s February 2013 memo argued that in order to “become the absolute best place to work, communication and collaboration will be important, so we need to be working side-by-side.” It went on: “Some of the best decisions and insights come from hallway and cafeteria discussions, meeting new people, and impromptu team meetings. Speed and quality are often sacrificed when we work from home. We need to be one Yahoo!, and that starts with physically being together.” The declaration ignited a firestorm of criticism, as it seemed to fly in the face of progressive thinking among both feminists and business leaders. A USA Today op-ed accused Mayer of “setting back the cause of working mothers.” Richard Branson tweeted that he was “perplexed” by the move and asserted: “Give people the freedom of where to work & they will excel.” Mayer’s move had some defenders, but most concluded that she was fighting the zeitgeist. Gallup’s new poll suggests Mayer may have been right — or at least that the question of telecommuting deserves a more nuanced analysis. On one hand, it found evidence of added productivity from those working outside the office: People actually work more hours at home, in part because they weren’t commuting or running errands at lunch. Some of the productivity increase also comes from being away from office distractions, says Gallup CEO Jim Clifton. But there is a point of diminishing returns, adds Clifton. People who spend 50% or more of their time working off site are less engaged than in-office counterparts and people who spend all of their time working remotely are twice as likely to feel disconnected from their work, Gallup found. Technologies allowing workers to share files and stay connected have helped smooth the way for more telework. But technology only gets you so far, says Rose Stanley, WorldatWork work-life practice leader, who herself works at home two days a week. “Social interaction gives you energy and makes you and your colleagues feel like you’re part of the same team,” says Stanley. “The sweet spot for making telework work is spending more of your working hours in the office than at home,” says Stanley. Intentionally or not, employer practices increasingly reflect this conclusion. While more companies are embracing telecommuting, it is mostly on a part-time basis. Today, 67% of companies allow workers to work remotely occasionally, up from 50% in 2008, according to the Society for Human Resource and Families and Work Institute’s 2014 National Study of Employers report. If you want to pitch a telework arrangement to your boss, first make sure your job can be done remotely. If you need special tools that are available only if you are physically present in the office or manage a lot of workers who are in the office, telecommuting may not work for you. Second, ask to do it on a trial basis. Prove that you can be productive and trusted to do your job without your boss’s eyes watching you, and it’ll be easier to make working remotely a regular gig.