John Glover Roberts

“ Mayo objects, however, to the Department's conclusion that residents who work more than 40 hours per week categorically cannot satisfy that requirement. Because residents' employment is itself educational, Mayo argues, the hours a resident spends working make him "more of a student, not less of one." ”

“ The Department's rule takes into account the SSA's concern that exempting residents from FICA would deprive residents and their families of vital disability and survivorship benefits that Social Security provides. Id., at 8605. Mayo wonders whether the full-time employee rule will result in residents being taxed under FICA but denied coverage by the SSA. The Government informs us, however, that the SSA continues to adhere to its longstanding position that medical residents are not students and thus remain eligible for coverage. ”

“ We have instructed that "neither antiquity nor contemporaneity with [a] statute is a condition of [a regulation's] validity." Smiley v. Citibank (South Dakota) , N. A., 517 U.S. 735, 740 (1996) . And we have found it immaterial to our analysis that a "regulation was prompted by litigation." Id., at 741. Indeed, in United Dominion Industries, Inc. v. United States, 532 U.S. 822, 838 (2001) , we expressly invited the Treasury Department to "amend its regulations" if troubled by the consequences of our resolution of the case. ”

“ Petitioners Mayo Foundation for Medical Education and Research, Mayo Clinic, and the Regents of the University of Minnesota (collectively Mayo) offer medical residency programs that provide such instruction. Mayo's residency programs,which usually last three to five years, train doctors primarily through hands-on experience. Residents often
page 2, slip opinion spend between 50 and 80 hours a week caring for patients, typically examining and diagnosing them, prescribing medication, recommending plans of care, and performing certain procedures. ”

“ The principles underlying our decision in Chevron apply with full force in the tax context. Chevron recognized that " [t] he power of an administrative agency to administer a congressionally created...program necessarily requires the formulation of policy and the making of rules to fill any gap left, implicitly or explicitly, by Congress." 467 U.S., at 843 (internal quotation marks omitted) . It acknowledged that the formulation of that policy might require "more than ordinary knowledge respecting the matters subjected to agency regulations." ”

“ Through the Social Security Act and related legislation, Congress has created a comprehensive national insurance system that provides benefits for retired workers, disabled workers, unemployed workers, and their families. ”

“ The rule also includes as an example the case of "Employee E," who is employed by "University V" as a medical resident. 69 Fed. Reg. 76409; Treas. Reg. §31.3121 (b) (10) –2 (e) , 26 CFR §31.3121 (b) (10) –2 (e) (Example 4) . Because Employee E's "normal work schedule calls for [him] to perform services 40 or more hours per week," the rule provides that his service is "not incident to and for the purpose of pursuing a course of study," and he accordingly is not an exempt "student" under §3121 (b) (10) . 69 ”

“ Pfennig, 541 U.S. 232, 242 (2004) (quoting United States v. Mead Corp., 533 U.S. 218, 227 (2001) ) . In this case, however, the parties disagree over the proper framework for evaluating an ambiguous provision of the Internal Revenue Code. ”