Despite some arguments to the contrary, the terms "nonprofit" and "not-for-profit" are synonymous. Basically, they are organizations that cannot distribute any financial surplus (profits) to shareholders, and thus benefit from certain tax exemptions. What some more narrowly call "nonprofits" are organizations classified as 501(c)(3) - in addition to not distributing profits, they are set up for charitable, educational, religious or scientific purposes. The AHA is listed as a 501(c)(6), which is a category used for business leagues, chambers of commerce and other organizations that - despite their non-profit-distributing nature - are created to promote a trade, profession or commercial activity (i.e. homebrewing). They are not listed or rated by Charity Navigator because, as a 501(c)(6), their membership dues are considered business expenses, rather than charitable donations, and are not tax deductible. Yes, the AHA is legit; no, it is not a scam.