501(c) organizations

A type of nonprofit public interest or public service organization, such as a lobbying group, social welfare group, or charitable foundation, identified by the U.S. Internal Revenue Service to indicate its tax status. Lobbying organizations are 501(c) (4) groups and not exempt from paying taxes. Contributors to political action committees (PACs), which are 501(c) (5) groups, cannot deduct from their taxes. Charitable foundations are 501(c) (3) groups and are tax exempt. To take advantage of tax laws, many 501(c) organizations form foundations outside of their functions. For example, the Sierra Club comprises several organizations, including a PAC that is a 501(c) (5) organization and a foundation that is a 501 (c) (3) organization.