Some workers in the United States are immigrants. And some of these immigrants work illegally—that is, they are not U.S. citizens and don’t have a green card or other documentation of their legal status.
All employers must verify that their employees are either U.S. citizens or nationals, or legal aliens authorized to work in the U.S.
You are not required to verify citizenship when you hire an IC. The government uses the common law right of control test to determine whether a worker is an employee or IC for immigration purposes. (See The Common Law Test for an in-depth discussion of the common law test.)
In addition, the verification requirements do not apply to any employees hired before November 7, 1986.
However, although you are not required to verify the immigration status of ICs or others coming within these exceptions, it is still illegal for you to hire any worker whom you know to be an illegal alien. The federal government can impose a fine up to $2,000 for the first offense.