 Greenaway was nominated by President Barack Obama on June 19, 2009, to a seat on the United States Court of Appeals for the Third Circuit vacated by Judge Samuel Alito.On February 9, 2010, he was confirmed by the Senate by an 84–0 vote and received commission on February 12, 2010.From 2002 to 2006, Greenaway was an adjunct professor at Rutgers School of Law in Newark, New Jersey.