The Internal Revenue Code lets nonprofits avoid federal income tax under different sections, but the section determines what the group can do politically. A 501(c)(3) charity offers tax-deductible donations but can't endorse candidates and can spend only an "insubstantial" share of its budget on lobbying. A 501(c)(4) social welfare organization can lobby without limit and engage in some campaign work, but donors don't get a tax deduction.
Think tanks usually pair the two structures. The 501(c)(3) arm produces research, hosts academics, and accepts tax-deductible gifts. A linked 501(c)(4) — sometimes called an "action" or "advocacy" affiliate — runs the lobbying, ad buys, and endorsements that would jeopardize the charity's tax status.
The dividing line is contested. The IRS rarely audits political activity, and courts have narrowed what counts as "campaign intervention," letting groups push the limits while keeping donors anonymous on both sides of the wall.
The same nonprofit network can collect tax-deductible donations to "educate" the public, then move that influence into elections through a sibling 501(c)(4) — without disclosing who paid for any of it.
People often think any nonprofit can lobby freely. In practice, the IRS section number on the tax return controls whether a group can endorse candidates, how much it can lobby, and whether donors get a write-off.
The same nonprofit network can collect tax-deductible donations to "educate" the public, then move that influence into elections through a sibling 501(c)(4) — without disclosing who paid for any of it.
People often think any nonprofit can lobby freely. In practice, the IRS section number on the tax return controls whether a group can endorse candidates, how much it can lobby, and whether donors get a write-off.