In August 2010, Smith joined the Department of Foreign Affairs and Trade as a Deputy Secretary. She was responsible for IT issues, the Americas, Africa, North Asia and international security issues. She shifted to the Department of the Prime Minister and Cabinet in September 2013, also as a Deputy Secretary. At PM&amp;C she was G20 Sherpa—the Prime Minister's personal envoy for the 2014 G20 Brisbane summit. She attended a G20 Sherpa meeting in Moscow in 2013 and chaired G20 meetings in Australia at Uluru, Sydney and Melbourne. She also led the development of the policy agenda for the event.