Opinion of the Court
which the employee was not on the job” counts as pay for services, and therefore ranks as wages. 532 U. S., at 210. Cleveland Indians then took up a discrete, “secondary issue” Nierotko presented, one not in contention here, i. e., whether for taxation purposes backpay is allocable to the tax period when paid rather than an earlier time-earned period. 532 U. S., at 211, 213–214, 219–220. Moreover, Quality Stores, which postdated Cleveland Indians, left no doubt that what qualifies under Nierotko as “wages” for benefit purposes also qualifies as such for taxation purposes. 572 U. S., at 146–147.
C
Loos presses a final reason why he should not owe RRTA taxes on his lost wages award. Loos argues, and the District Court held, that the RRTA’s tax on employees does not apply to personal injury damages. He observes that the RRTA taxes “the income of each employee.” 26 U. S. C. §3201(a)–(b) (emphasis added). He then cites a provision of the Internal Revenue Code, 26 U. S. C. §104(a)(2). This provision exempts “damages… received… on account of personal physical injuries” from federal income taxation by excluding such damages from “gross income.” Loos urges that the exclusion of personal injury damages from “gross income” should carry over to the RRTA’s tax on the “income” of railroad workers, §3201(a)–(b).
The argument is unconvincing. As the Government points out, the District Court, echoed by Loos, conflated “the distinct concepts of ‘gross income,’ [a prime component of] the tax base on which income tax is collected, and ‘compensation,’ the separately defined category of payments that are taxable under the RRTA.” Brief for United States as Amicus Curiae 15. Blending tax bases that Congress kept discrete, the District Court and Loos proffer a scheme in which employees pay no tax on damages
