 Fedderly is a notable teacher of tuba, euphonium and general respiratory techniques for playing brass instruments.He lectured at the Peabody Institute of the Johns Hopkins University until 2000 and rejoined the faculty in 2009, he has been on the faculty of The Juilliard School since 2002 and has also held teaching positions at DePaul University, University of Maryland, College Park and The Catholic University of America.He is a member of the Board of Directors of the International Tuba Euphonium Association, where he served as treasurer from 2008–10, and is the proprietor of the Baltimore Brass Company, a large brass sales and repair shop in Catonsville, just west of Baltimore.