The American Civil Liberties Union (ACLU) is a 501 (c) (4) – a tax-exempt social welfare organization that engages in political and/or lobbying efforts to further its mission which means donations are treated as membership fees and, are therefore not tax deductible.
The American Civil Liberties Union Foundation (ACLU Foundation) is a 501 (c) (3) – a tax-exempt organization whose donations are tax deductible because their political and/or lobbying efforts are very limited.
Although both organizations are set up as different types of tax-exempt non-profits, they both operate out of the same office in New York City. So, when people talk about the ACLU, it is necessary to look at both organizations. In addition, it is important to note there are state affiliate offices nationwide that are separate tax-exempt organizations. Read more