Reports of alien minors being separated from their parents at the U.S. border have raised questions about the Department of Homeland Security's (DHS's) authority to detain alien families together pending the aliens' removal proceedings, which may include consideration of claims for asylum and other forms of relief from removal. The Immigration and Nationality Act (INA) authorizes-and in some case requires-DHS to detain aliens pending removal proceedings. However, neither the INA nor other federal laws specifically address when or whether alien family members must be detained together. DHS's options regarding the detention or release of alien families are significantly restricted by a binding settlement agreement from a case in the U.S. District Court for the Central District of California now called Flores v. Sessions. The "Flores Settlement" establishes a policy favoring the release of alien minors, including accompanied alien minors, and requires that those alien minors who are not released from government custody be transferred within a brief period to non-secure, state-licensed facilities. DHS indicates that few such facilities exist that can house adults and children together. Accordingly, under the Flores Settlement and current circumstances, DHS asserts that it generally cannot detain alien children and their parents together for more than brief periods. Following an executive order President Trump issued that addressed alien family separation, the Department of Justice filed a motion to modify the Flores Settlement to allow for the detention of alien families in unlicensed facilities for longer periods. The district court overseeing the settlement rejected that motion, much as it has rejected similar motions to modify the settlement filed by the government in recent years. (The U.S. Court of Appeals for the Ninth Circuit has affirmed the earlier rulings but has not yet reviewed the most recent ruling.) In its most recent motion, the government has argued, among other things, that a preliminary injunction entered in a separate litigation, Ms. L v. ICE, which generally requires the government to reunite separated alien families and refrain from separating families going forward, supports a modification of the Flores Settlement to allow indefinite detention of alien minors alongside their parents. Congress, for its part, could largely override the Flores Settlement legislatively, although constitutional considerations relating to the rights of aliens in immigration custody may inform the permissible scope and effect of such legislation.