What is a 501(c)(4) organization?

A 501(c)(4) organization is a nonprofit entity granted tax-exempt status under Section 501(c)(4) of the Internal Revenue Code (26 U.S.C. Section 501(c)(4)), which covers 'civic leagues or organizations not organized for profit but operated exclusively for the promotion of social welfare.' The Internal Revenue Service interprets 'exclusively' to mean 'primarily': a 501(c)(4) may engage in political activity -- voter registration, voter mobilization, issue advocacy, lobbying, and political advertising -- as long as political activity does not constitute its primary purpose. The IRS applies a facts-and-circumstances test, examining the organization's total activities, to determine whether it qualifies. A 501(c)(4) is distinct from a 501(c)(3) charitable organization (which may not engage in political campaign activity at all and is subject to strict lobbying limits), from a 527 political organization (which exists explicitly to influence elections and is subject to its own IRS and FEC disclosure rules), and from a PAC or super PAC (which are registered with the FEC and required to publicly disclose donors above reporting thresholds).

The key legal development that expanded 501(c)(4) political activity in federal elections was Citizens United v. Federal Election Commission, 558 U.S. 310 (January 21, 2010). The plaintiff in that case -- Citizens United -- was itself a 501(c)(4) nonprofit corporation that had produced 'Hillary: The Movie,' a critical documentary about Hillary Clinton, and sought to distribute it via video-on-demand and air advertisements for it close to the 2008 primary elections. The Supreme Court held 5-4 that the First Amendment prohibits the government from restricting independent political expenditures by corporations, associations, and labor unions, including nonprofit corporations. This ruling -- combined with SpeechNow.org v. FEC, 599 F.3d 686 (D.C. Circuit, March 26, 2010), which extended the same logic to contributions to groups making only independent expenditures -- enabled 501(c)(4) organizations to make unlimited independent expenditures directly from their organizational funds to advocate for or against federal candidates, provided those expenditures are not coordinated with any campaign.

The 'dark money' mechanism arises from the intersection of 501(c)(4) donor privacy and the FEC's disclosure requirements for political spending. When an individual donates money to a 501(c)(4), that donation does not appear in any publicly searchable federal disclosure database. The 501(c)(4) may then contribute to a super PAC -- that contribution is disclosed by the super PAC in its FEC filings and is publicly searchable at fec.gov, showing the 501(c)(4) organization's name and the amount given. However, the names of the individuals who funded the 501(c)(4) are not visible in the super PAC's FEC filing. The flow is: individual donor (name not publicly disclosed) -- 501(c)(4) organization (its name disclosed on the super PAC's FEC report) -- super PAC -- election spending (disclosed). A researcher examining the super PAC's filings can see that a named 501(c)(4) organization donated a specified amount, but cannot determine from public FEC records which specific individuals funded that 501(c)(4).

501(c)(4) organizations must comply with several legal requirements. They must file a Form 8976 electronic notice with the IRS within 60 days of organizing (a requirement introduced in 2016). They file an annual Form 990, which is publicly available on the IRS website, but donor identification information filed with the IRS is kept confidential by federal law (26 U.S.C. Section 6104(b)). For federal election spending specifically, a 501(c)(4) that makes electioneering communications -- broadcast, cable, or satellite ads clearly identifying a federal candidate within 30 days of a primary or 60 days of a general election -- must file a disclosure report with the FEC under 52 U.S.C. Section 30104(f), identifying the ad, the candidate referenced, and each person who gave $1,000 or more to fund that specific communication. A 501(c)(4) that makes independent expenditures above $250 in a calendar year must report those expenditures to the FEC under 52 U.S.C. Section 30104(g). These FEC filings disclose the spending itself; they do not require disclosure of all general donors to the 501(c)(4). In Americans for Prosperity Foundation v. Bonta, 594 U.S. 595 (2021), the Supreme Court held 6-3 that California's requirement that nonprofits disclose their major donors to state officials as a condition of charitable solicitation was unconstitutional under the First Amendment right of association, narrowing the reach of state-level disclosure requirements for 501(c)(4) donors.

For the 2028 presidential election, 501(c)(4) organizations are expected to be a significant channel for political spending by corporations, unions, and individuals who wish to influence the election while keeping their identities out of publicly searchable FEC databases. They may support or oppose 2028 candidates through independent expenditures and electioneering communications, provided political activity does not become their primary purpose. By donating to super PACs, they can channel unlimited funds into the concentrated independent-expenditure campaigns that major 2028 presidential candidates are expected to attract. All super PAC filings, including contributions received from 501(c)(4) organizations, are publicly searchable at fec.gov; 501(c)(4) spending on electioneering communications and independent expenditures is separately disclosed to the FEC. The practical effect is that voters and journalists can track the dollar amounts and the names of 501(c)(4) organizations involved in 2028 campaign spending, but not always the individual donors who funded those organizations.