In 1953, Koschatzky joined the Office of the Styrian Government, and moved in 1955 to the Neue Galerie at the Universalmuseum Joanneum in Graz where he worked from 1956 to 1961 as a director.
From 1 January 1962 to 1 October 1986 he was appointed, by Minister of Education Henry Drimmel, as director of the collection of Prints and Drawings at the Albertina in Vienna.