Research 1 Doctoral Universities – Very high research activity

There are 146 institutions that are classified as "R1: Doctoral Universities – Very high research activity" in the Carnegie Classification of Institutions of Higher Education as of the 2021 update.

These universities have a very high level of both research activity and per capita in such research activity, using aggregate data to determine both measurements. Among the 50 U.S. states and the national capital of Washington, D.C., only five states do not have an R1 level university: Alaska, Idaho, South Dakota, Vermont, and Wyoming.

Research 2 Doctoral Universities – Very high research activity

There are 133 institutions that are classified as "R2: Doctoral Universities – High research activity" in the Carnegie Classification of Institutions of Higher Education as of the 2021 update.

These universities have a very high level of either research activity or per capita in such research activity, using aggregate data to determine both measurements, while having a very low level on the other qualification. In other words, these institutions either lack research facilities or do not have a lot of people conducting research at their respective institution.

Special Focus Research Institutions

There are 23 institutions that are classified as "Special Focus – Research Institutions" in the Carnegie Classification of Institutions of Higher Education as of the 2021 update.

This new category has the same threshold for inclusion as R1 and R2 schools do (At least twenty research doctorates awarded and five million dollars in research expenditures), but unlike R1 and R2 schools, they only award degrees in a single academic area.