Statistics of U.S. Businesses (SUSB) use of legal form of organization (LFO) and how the categories have changed throughout the years.

[2008 +]
1. C-Corporation and other corporate legal forms of organization - An incorporated business that is granted a charter recognizing it as a separate legal entity having its own privileges, and liabilities distinct from those of its members.
2. S-Corporation - A form of Corporation where the entity does not pay any federal income taxes. The corporation's income or losses are divided among and passed to its shareholders. The shareholders must then report the income or loss on their own individual income tax returns.
3. Partnership - An unicorporated business where two or more persons join to carry on a trade or business with each having a shared financial interest in the business.
4. Sole Proprietorships - An unincorporated business with a sole owner.
5. Non-profits - An organization that does not distribute surplus funds to its owners or shareholders, but instead uses surplus funds to help pursue its goals. Most non-profit organizations are exempt from taxes.
6. Government - A business that taxpayers primarily fund. Most government businesses are out of scope to the Statistics of U.S. Businesses (SUSB) program.
7. Other (trusts, estates, cooperatives with undetermined tax status, etc.)

[2007]
1. Corporations (subject to taxes) - Enterprises legally incorporated under state laws.
2. Tax-Exempt Corporations - Enterprises legally incorporated under state laws, not subject to taxes.
3. S-Corporations - Corporation with 75 or fewer shareholders, that has elected and qualified for a special tax status.
4. Partnerships - Unincorporated enterprises owned by two or more persons having financial interest in the business.
5. Sole Proprietorships - Unincorporated enterprises owned by one person.
6. Government
7. Other (trusts, estates, cooperatives with undetermined tax status, etc.)
8. Tax-Exempt Other (religious organizations, etc.)

[2002-2006]
1. Corporations (subject to taxes) - Enterprises legally incorporated under state laws.
2. Tax-Exempt Corporations - Enterprises legally incorporated under state laws & not subject to taxes.
3. Partnerships - Unincorporated enterprises owned by two or more persons having financial interest in the business.
4. Sole Proprietorships - Unincorporated enterprises owned by one person.
5. Other (trusts, estates, cooperatives with undetermined tax status, etc.) - Enterprises that are formed by other legal form of organization.
6. Tax-Exempt Other (religious organizations, etc.) - Enterprises that are formed by other legal form of organization & not subject to taxes.
7. Unknown - Enterprises with unknown legal form of organization.

[1988-2001]
1. Corporations - Enterprises legally incorporated under state laws.
2. Partnerships - Unincorporated enterprises owned by two or more persons having financial interest in the business.
3. Sole Proprietorships - Unincorporated enterprises owned by one person.
4. Nonprofit Organizations - Enterprises with non-profit status (tax-exempt).
5. Other (Associations, Trust, Joint Ventures, Estates, etc.) - Enterprises that are formed by other legal form of organization.
6. Unknown - Enterprises with unknown legal form of organization.