Maine allows each university and college to decide whether to permit concealed handguns on campus or in buildings. See:
As of September 29, 2016, no public or private university permits concealed guns on campus grounds or in buildings.
Disclaimer: Policies are subject to change at any time, both during and between school years. In addition, individual school policies commonly include more details than can be succinctly captured by ArmedCampuses.org. Each school should be consulted for its most accurate, up-to-date policy.