Federal tax rules prohibit section 501(c)(3) organizations from participating or intervening in a political campaign in support of or in opposition to a candidate for elected public office. However, organizations may lobby, educate voters, encourage voter registration and participation, and advocate for issues in a nonpartisan manner. This guide gives background information about IRS definitions of organization types and details the many types of activities that 501(c)(3) organizations are and are not allowed to pursue.