Reentry and Reunification Act of 2018 This bill directs the Department of Homeland Security to admit an otherwise inadmissible alien for lawful permanent residence if such person is the spouse, parent, or guardian of a U.S. citizen; has been a person of good moral character; has been removed from the United States or is subject to removal; is not inadmissible or deportable under specified grounds; has not participated in the persecution of any person on account of race, religion, nationality, or political opinion; has not been convicted of federal or state crimes with a term of imprisonment of more than one year; and in the case of an alien subject to removal, has been continuously present in the United States for four years.