You are required to complete and retain a Form I-9 for every employee you hire for employment in the United States, except for:
Individuals hired on or before Nov. 6, 1986, who are continuing in their employment and have a reasonable expectation of employment at all times. (Some limitations to this exception apply.) Also excepted are individuals hired for employment in the Commonwealth of the Northern Mariana Islands (CNMI) on or before Nov. 27, 2009.
Individuals employed for casual domestic work in a private home on a sporadic, irregular or intermittent basis.
Independent contractors or individuals providing labor to you if they are employed by a contractor providing contract services (for example, employee leasing or temporary agencies).
Individuals not physically working in the U.S.
Federal law prohibits individuals or businesses from contracting with an independent contractor knowing that the independent contractor is not authorized to work in the U.S.