He then moved to New York City and maintained a steady career as a freelance musician for four years until 1967.
In 1967, Nyfenger joined the flute faculty of the Yale School of Music and also served as the chairman of the wind department.
[6] The Thomas Daniel Nyfenger Prize is awarded annually by the Yale School of Music "to a student who has demonstrated the highest standard of excellence in woodwind playing".
; the late Philip Dikeman, former assistant principal flutist of the Detroit Symphony Orchestra, and former Associate Professor of Flute at the Blair School of Music at Vanderbilt University; Terri Sundberg, Professor of Flute at the University of North Texas College of Music in Denton, TX.
It is a collection of Nyfenger's written thoughts which were found, compiled, and edited by Edward Joffe.