From the Institute's founding through Summer 1994 all courses were graduate level and numbered within the 100-999 range.
In Fall 1994 CIIS introduced its bachelor's degree completion program. From Fall 1994 to Summer 2000 course numbers ranging from 300-499 indicate undergraduate level; those ranging from 500-999 indicate graduate level.
From Fall 2000 to the present, a fourth digit was added to the course numbers. The 1000-4999 range indicates undergraduate level; the 5000-9999 range indicates graduate level.
CIIS offers workshops to the public on themes related to the Institute's mission. In Fall 1993 CIIS began offering a subset of these workshops for academic credit to its matriculated students. From Fall 1993 to Summer 2000 these workshops were assigned course numbers within the 001-999 range and from Fall 2000 to the present in the 0001-9999 range. All of these workshops bestow graduate-level credit.