The LLC is typically the best choice for smaller entities. The LLC structure provides a great deal of ownership flexibility in that an LLC may have any number of Members (owners) including non-US citizens and subsidiary companies. LLCs are also able to distribute several different classes of stock or ownership interest. However, their owners are typically required to pay a self-employment tax.
PLLC, Professional Limited Liability Company: some states do not allow certain professionals to form an LLC that would limit the liability that results from the services professionals provide such as doctors, medical care; lawyers, legal advice; and accountants, accounting services; architects, architectural services; when the company formed offers the services of the professionals. Instead those states allow a PLLC or in the LLC statutes, the liability limitation only applies to the business side, such as creditors of the company, as opposed to the client/customer service side, the level of medical care, legal services, or accounting provided to clients. This is meant to maintain the higher ethical standards that these professionals have committed themselves to by becoming licensed in their profession and to prevent them from being immune (or at least limit their immunity) to malpractice suits.
LLC, LC, Ltd. Co., Limited Liability Company: a form of business whose owners enjoy limited liability, but which is not a corporation. Allowable abbreviations vary by state. Note that in some states Ltd. by itself is not a valid abbreviation for an LLC, because in some states (e.g. Texas), it may denote a corporation instead. See also Series LLC. For U.S. federal tax purposes, in general, an LLC with two or more members is treated as a partnership, and an LLC with one member is treated as a sole proprietorship.