The Trump administration will end a longstanding requirement that certain nonprofit organizations disclose the names of large donors to the Internal Revenue Service, a move that will allow some political groups to shield their sources of funding from government scrutiny.
The change, which has long been sought by conservatives and Republicans in Congress, will affect thousands of labor unions, social clubs and political groups as varied as arms of the AARP, the United States Chamber of Commerce, the National Rifle Association and Americans for Prosperity, which is funded partly by the billionaire brothers Charles and David Koch.
Such groups have played an increasingly prominent role in American politics in the wake of the Supreme Court’s 2010 ruling in a case brought by the nonprofit group Citizens United, which empowered them to spend unlimited money on campaign ads.
Treasury officials said the reporting change — which affects contributions known as dark money because their source is hidden — would protect privacy and reduce compliance costs for nonprofit organizations. The I.R.S. could still request donor information from groups in the rare event that it was needed for tax scrutiny.
