Opinion of the Court
so didn’t require notice and comment under §1395hh(a)(2)—because the statute itself required it to count Part C patients in the Medicare fraction. But we need not consider this argument either, this time because the government hasn’t pursued it and we normally have no obligation to entertain grounds for reversal that a party hasn’t presented. Far from suggesting that the Medicare Act supplies the controlling legal standard for determining whether to count Part C patients, the government has insisted that the statute “does not speak directly to the issue,” Brief for Appellant in Northeast Hospital Corp. v. Sebelius, No. 10–5163 (CADC), p. 22, and thus leaves a “ ‘gap’ ” for the agency to fill, Brief for Appellee in Allina v. Price, No. 16–5255 (CADC), p. 50 (quoting Northeast Hospital Corp., 657 F. 3d, at 13). The courts below accepted the government’s submission, and the government hasn’t sought to take a different position in this Court. So we express no opinion on whether the statute in fact contains such a “gap.” We hold simply that, when the government establishes or changes an avowedly “gap”-filling policy, it can’t evade its notice-and-comment obligations under §1395hh(a)(2) on the strength of the arguments it has advanced in this case.
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The judgment of the court of appeals is
JUSTICE KAVANAUGH took no part in the consideration or decision of this case.
