A 527 group or a 527 organization is an IRS classification for a type of political advocacy group. This code applies to groups such as, “a party, committee, association, fund, or other organization (whether or not incorporated) organized and operated primarily for the purpose of directly or indirectly accepting contributions or making expenditures, or both, for an exempt function.”
So, technically almost all political committees, including PACs and super PACs are “527s,” as long as they do not “expressly advocate” for the election or defeat of a candidate or party.
There are no limits on contributions to a 527 group, and no restrictions on who may contribute. There is also no spending limits imposed on these organizations – however they are required to file with the IRS and publicly disclose their donors and file reports of their contributions and expenditures.