Reentry and Reunification Act This bill directs the Department of Homeland Security (DHS) to admit certain aliens for lawful permanent residence if the alien is the spouse, parent, or guardian of a U.S. citizen. Qualifying aliens shall be those who were removed from the United States before the bill's enactment, or are subject to a removal order or in removal proceedings on the bill's enactment date. A qualifying alien shall also (1) be of good moral character; (2) not be deportable or inadmissible for various grounds, including those related to health or having been convicted of certain crimes; (3) not have participated in the persecution of any person on account of characteristics such as race, religion, or nationality; and (4) not have been convicted for certain crimes under federal or state law where the maximum sentence was more than one year. DHS may waive the requirement relating to a conviction for a state or federal crime and other specified requirements for humanitarian, family unity, or public interest purposes. For an alien subject to a removal order or under removal proceedings, the alien must have been continuously physically present in the United States for the four years before the bill's enactment date.