"On December 26, 2012, Hanrahan was traded to the Boston Red Sox (along with Brock Holt) for Jerry Sands, Stolmy Pimentel, Iván DeJesús, Jr. and Mark Melancon.On May 2, Hanrahan got his 100th career save in a 3–1 victory over the Toronto Blue Jays, which was his first save since coming off the disabled list.