Under the Illegal Immigration Reform and Immigrant Responsibility Act of 1996 (IIRIRA), the Attorney General has the discretion to “cancel removal” and adjust the status of certain nonpermanent residents. §1229b(b). A nonpermanent resident must meet certain enumerated criteria, such as the noncitizen must have “been physically present in the United States for a continuous period of not less than 10 years immediately preceding the date of [an] application” for cancellation of removal. §1229b(b)(1)(A). Under the stop-time rule “any period of . . . continuous physical presence in the United States shall be deemed to end . . . when the alien is served a notice to appear under section 1229(a) of this title.” Under the stop-time rule “any period of . . . continuous physical presence in the United States shall be deemed to end . . . when the alien is served a notice to appear under section 1229(a) of this title.” §1229b(d)(1)(A). Section 1229(a) provides that “written notice (in this section referred to as a ‘notice to appear’) shall be given . . . to the alien . . . specifying” in part the time and place at which the [removal] proceedings will be held. The Government can “change or postpone . . . the time and place of [the removal] proceedings.” §1229(a)(2)(A). If a noncitizen fails to appear at a removal proceeding, he “shall be ordered removed in absentia” if the Government “establishes by clear, unequivocal, and convincing evidence that the written notice was so provided and that the alien is removable.” §1229a(b)(5)(A). In 1997, the Attorney General promulgated a regulation stating that a “notice to appear” served on a noncitizen need only provide “the time, place and date of the initial removal hearing, where practicable.” DHS almost always serves noncitizens with notices that fail to specify the time, place, or date of initial removal hearings whenever the agency deems it impracticable to include such information. These notices state that the times, places, or dates of the initial hearings are “to be determined.” The Board of Immigration Appeals (BIA) has concluded that the statutory phrase “notice to appear ‘under section [1229](a)’” in the stop-time rule “merely specifies the document the DHS must serve on the alien to trigger the ‘stop-time’ rule,” but otherwise imposes no “substantive requirements” as to what information that document must include to trigger the stop-time rule. P is a native and citizen of Brazil. In 2000, at age 19, he was admitted to the United States as a temporary “non-immigrant visitor.” His visa expired and he remained in the United States. P is married and has two young daughters, both of whom are United States citizens. He works as a handyman and, according to submissions before the Immigration Court, is a well-respected member of his community. In 2006, P was arrested in Massachusetts for operating a vehicle while under the influence of alcohol. While detained DHS served him with a document labeled “Notice to Appear.” The notice did not specify the date and time of P’s removal hearing. On August 9, 2007, the Immigration Court attempted to mail P a more specific notice setting the date and time for his initial removal hearing for October 31, 2007, at 9:30 a.m. That notice was sent to the wrong address. P did provide the correct address. P failed to appear, and the Immigration Court ordered him removed in absentia. In 2013, after P had been in the country for more than 10 years, he was arrested for a minor motor vehicle violation and was detained by DHS. P applied for cancellation of removal, arguing that the stop-time rule was not triggered because the document lacked information about the time and date of his removal hearing. The court disagreed. The BIA dismissed P’s appeal. The Court of Appeals found that the stop-time rule in §1229b(d)(1) is ambiguous because it “does not explicitly state that the date and time of the hearing must be included in a notice to appear in order to cut off an alien’s period of continuous physical presence.” It then held that the BIA’s interpretation of the stop-time rule was a permissible reading of the statute. The Supreme Court granted certiorari.