After an alien has been legally "removed" from the United States, federal criminal law makes it a felony for that person to reenter, or be found in, the country without approval of the government.  It is not only a crime to reenter the country after removal, it is also a crime for a person to reenter the country after having been denied admission to the U.S., excluded from the U.S., deported from the U.S., or if he or she left the country while an order of exclusion, deportation, or removal was outstanding.

If an alien is found to have reentered the country after removal, he or she will face a fine, imprisonment for up to 2 years, or both.  If an alien reenters the U.S., without government approval, after a criminal felony conviction for a non-aggravated felony, or after three or more misdemeanor convictions for drug-related crimes or crimes against persons, he or she will be fined, imprisoned for up to 10 years, or both.