(1)The built-in gain tax only applies to S Corporations that were previously C Corporations. (2)S Corporations can have a second class of stock, non-voting common stock, as well as common stock. (3)Although unusual, some LLCs known as master limited partnerships can be publicly traded, but they are usually taxed as C Corporations instead of partnerships.
SOURCES: Richard A. Eisner & Co. LLP, Hamilton & Rose CPAs, and American Express Tax and Business Services.