"A 501(c) organization is a nonprofit organization in the federal law of the United States according to Section 501(c) and is one of over 29 types of nonprofit organizations exempt from some federal income taxes. Sections 503 through 505 set out the requirements for obtaining such exemptions. Many states refer to Section 501(c) for definitions of organizations exempt from state taxation as well. 501(c) organizations can receive unlimited contributions from individuals, corporations, and unions."