The University of Washington is a governmental tax exempt entity. The University's activities are generally free from federal tax unless they are unrelated to the mission of the UW. See Unrelated Business Income.
The UW is not a 501(c)3, although for tax purposes it is quite similar. On various occasions, grantors, donors and others request proof of our tax exempt status. The most recent IRS documentation regarding our tax exempt status can be found here. A letter with respect to our Canadian donors is also available here.