For colleges and universities in the United States, our membership fee is based on the Carnegie Classification of Institutions of Higher Education. From the Carnegie database, we use their "Basic" measure of institution type, which is based on student headcount, degree programs, and the amount of research conducted at the institution (among other variables). Rather than having 33 different fees, we've collapsed the institution types down to four.
For fiscal year 2018/19, REN-ISAC is re-aligning some institution types with different fee categories. Click here for more information.