MR. JUSTICE STEWART delivered the opinion of the Court.
The Commissioner of Internal Revenue has long maintained that a taxpayer traveling on business may deduct the cost of his meals only if his trip requires him to stop for sleep or rest. The question presented here is the validity of that rule.
The respondent in this case was a traveling salesman for a wholesale grocery company in Tennessee.1 He customarily left home early in the morning, ate breakfast and lunch on the road, and returned home in time for dinner. In his income tax returns for 1960 and 1961, he deducted the cost of his morning and noon meals as "traveling expenses" incurred in the pursuit of his business "while away from home" under § 162 (a) (2) of the Internal Revenue Code of 1954.2 Because the respondent's daily trips required neither sleep nor rest, the Commissioner disallowed the deductions, ruling that the cost of the respondent's meals was a "personal, living" expense under § 2623 rather than a travel expense under § 162 (a) (2). The respondent paid the tax, sued for a refund in the District Court, and there received a favorable jury verdict.4 The Court of Appeals for the Sixth Circuit affirmed, holding that the Commissioner's sleep or rest rule is not "a valid regulation under the present statute." 369 F.2d 87, 90. In order to resolve a conflict among the circuits on this recurring question of federal income tax administration,5 we granted certiorari. 388 U.S. 905.
Under § 162 (a) (2), taxpayers "traveling . . . away from home in the pursuit of a trade or business" may deduct the total amount "expended for meals and lodging."6 As a result, even the taxpayer who incurs substantial hotel and restaurant expenses because of the special demands of business travel receives something of a windfall, for at least part of what he spends on meals represents a personal living expense that other taxpayers must bear without receiving any deduction at all.7 Not surprisingly, therefore, Congress did not extend the special benefits of § 162 (a) (2) to every conceivable situation involving business travel. It made the total cost of meals and lodging deductible only if incurred in the course of travel that takes the taxpayer "away from home." The problem before us involves the meaning of that limiting phrase.
In resolving that problem, the Commissioner has avoided the wasteful litigation and continuing uncertainty that would inevitably accompany any purely case-by-case approach to the question of whether a particular taxpayer was "away from home" on a particular day.8 Rather than requiring "every meal-purchasing taxpayer to take pot luck in the courts,"9 the Commissioner has consistently construed travel "away from home" to exclude all trips requiring neither sleep nor rest,10 regardless of how many cities a given trip may have touched,11 how many miles it may have covered,12 or how many hours it may have consumed.13 By so interpreting the statutory phrase, the Commissioner has achieved not only ease and certainty of application but also substantial fairness, for the sleep or rest rule places all one-day travelers on a similar tax footing, rather than discriminating against intracity travelers and commuters, who of course cannot deduct the cost of the meals they eat on the road. See Commissioner v. Flowers, 326 U.S. 465.
Any rule in this area must make some rather arbitrary distinctions,14 but at least the sleep or rest rule avoids the obvious inequity of permitting the New Yorker who makes a quick trip to Washington and back, missing neither his breakfast nor his dinner at home, to deduct the cost of his lunch merely because he covers more miles than the salesman who travels locally and must finance all his meals without the help of the Federal Treasury.15 And the Commissioner's rule surely makes more sense than one which would allow the respondent in this case to deduct the cost of his breakfast and lunch simply because he spends a greater percentage of his time at the wheel than the commuter who eats breakfast on his way to work and lunch a block from his office.
The Court of Appeals nonetheless found in the "plain language of the statute" an insuperable obstacle to the Commissioner's construction. 369 F.2d 87, 89. We disagree. The language of the statute—"meals and lodging. . . away from home"—is obviously not self-defining.16 And to the extent that the words chosen by Congress cut in either direction, they tend to support rather than defeat the Commissioner's position, for the statute speaks of "meals and lodging" as a unit, suggesting—at least arguably—that Congress contemplated a deduction for the cost of meals only where the travel in question involves lodging as well.17 Ordinarily, at least, only the taxpayer who finds it necessary to stop for sleep or rest incurs significantly higher living expenses as a direct result of his business travel,18 and Congress might well have thought that only taxpayers in that category should be permitted to deduct their living expenses while on the road.19 In any event, Congress certainly recognized, when it promulgated § 162 (a) (2), that the Commissioner had so understood its statutory predecessor.20 This case thus comes within the settled principle that "Treasury regulations and interpretations long continued without substantial change, applying to unamended or substantially reenacted statutes, are deemed to have received congressional approval and have the effect of law." Helvering v. Winmill, 305 U.S. 79, 83; Fribourg Nav. Co. v. Commissioner, 383 U.S. 272, 283.
Alternatives to the Commissioner's sleep or rest rule are of course available.21 Improvements might be imagined.22 But we do not sit as a committee of revision to perfect the administration of the tax laws. Congress has delegated to the Commissioner, not to the courts, the task of prescribing "all needful rules and regulations for the enforcement" of the Internal Revenue Code. 26 U. S. C. § 7805 (a). In this area of limitless factual variations, "it is the province of Congress and the Commissioner, not the courts, to make the appropriate adjustments." Commissioner v. Stidger, 386 U.S. 287, 296. The role of the judiciary in cases of this sort begins and ends with assuring that the Commissioner's regulations fall within his authority to implement the congressional mandate in some reasonable manner. Because the rule challenged here has not been shown deficient on that score, the Court of Appeals should have sustained its validity. The judgment is therefore
MR. JUSTICE MARSHALL took no part in the consideration or decision of this case.
MR. JUSTICE DOUGLAS, with whom MR. JUSTICE BLACK and MR. JUSTICE FORTAS concur, dissenting.
The statutory words "while away from home," 26 U. S. C. § 162 (a) (2), may not in my view be shrunken to "overnight" by administrative construction or regulations. "Overnight" injects a time element in testing deductibility, while the statute speaks only in terms of geography. As stated by the Court of Appeals:
"In an era of supersonic travel, the time factor is hardly relevant to the question of whether or not travel and meal expenses are related to the taxpayer's business and cannot be the basis of a valid regulation under the present statute." Correll v. United States, 369 F.2d 87, 89-90.
I would affirm the judgment below.