BREYER, J., dissenting
substantive legal standards”). If the Court is going to effectively exempt interpretive rules from the notice-and-comment requirement, why not simply say so?
Nor does the Court’s resolution of this particular case offer clarity as to the scope of the statute. The Court holds that the agency must provide notice and comment before including Medicare Part C patients in the Medicare fraction. But it does not explain why that agency decision “establishes or changes a substantive legal standard.” Is it because the decision “affects a hospital’s right to payment”? Ante, at 6. Is it because the decision’s financial impact is “considerabl[e]”? Ante, at 3−4. Is it because the agency had previously sought to adopt the same policy through notice and comment? Ante, at 4. The Court does not say.
This lack of explanation aggravates the potential burden that the Court’s opinion already imposes upon the Medicare program. It may also lead to legal challenges to the validity of interpretive rules (or even procedural rules) previously thought to have been settled. And it will thereby increase the confusion that is inevitable once the Court rejects the settled and readily available principles that courts have learned to use to identify substantive rules under the APA. These potential adverse consequences are, in my view, persuasive evidence that Congress did not intend the statute to be construed in this way.
To consider these consequences in no way invades Congress’ constitutional authority to “weigh the costs and benefits of different approaches and make the necessary policy judgment.” Ante, at 16. Congress exercised that authority when it passed the Medicare Act’s notice-and-comment provisions. But it used language that even the Court describes as “enigmatic,” ante, at 10, and our role as judges is to decipher that enigma. Examining the potential consequences of each competing interpretation helps us perform that task, as we can presume that Congress
