Opinion of the Court
Opinion of Gorsuch, J.
penalty for nonwillful violations. Brief for United States 32. But what does this prove? Assuming the Secretary could require more frequent reports (a question not before us), that would mean the Secretary could also require less frequent reports (for example, every other year). Likewise, the Secretary could reduce the amount of information required in those reports (say, expanding the tick-box option to all filers, not just those with 25 or more accounts). Perhaps more fundamentally, whether the Secretary may lawfully ordain more or fewer reports does nothing to answer the question whether the Secretary may impose nonwillful penalties on a per-report or per-account basis. That question would still remain. Reply Brief 7–8.
C
To the extent doubt persists at this point about the best reading of the BSA, a venerable principle supplies a way to resolve it. Under the rule of lenity, this Court has long held, statutes imposing penalties are to be “construed strictly” against the government and in favor of individuals. Commissioner v. Acker, 361 U. S. 87, 91 (1959). Following that rule here requires us to favor a per-report approach that would restrain BSA penalties over a per-account theory that would greatly enhance them.
The government resists this conclusion by seeking to distinguish Acker. That case involved a penalty provision in the Internal Revenue Code, the government emphasizes, while this case involves a penalty provision in the BSA. Brief for United States 44–45. But that distinction makes no difference. The rule of lenity is not shackled to the Internal Revenue Code or any other chapter of federal statutory law. Instead, as Acker acknowledged, “[t]he law is settled that penal statutes are to be construed strictly,” and an individual “is not to be subjected to a penalty unless the words of the statute plainly impose it.” 361 U. S., at 91 (in-
