Rackham Graduate School Office of Graduate Fellowships is a comprehensive resource listing many sources of aid: http://www.rackham.umich.edu/Fellowships/index.html

Prospective and returning students should also contact the fellowship chairperson in their respective department.  Most departments have funds to cover graduate student expenses, including tuition, and offer a monthly stipend. These funds may be in the form of grants, fellowships, research and teaching assistantships, and tuition waivers.