Two years ago, Loper Bright Enterprises v. Raimondo removed the interpretive buffer that once indirectly protected municipalities relying on federal agency interpretations. Last week, I argued that municipalities need a pre-adoption risk assessment tool—a way to evaluate regulatory text before it takes effect. But Loper Bright is not the only structural change municipal attorneys need to reckon with. Corner Post, Inc. v. Board of Governors of the Federal Reserve System may allow newly injured plaintiffs to challenge certain federal agency actions years after those actions became final—and that exposure doesn’t stop at an ordinance’s own effective date.
Corner Post held that an Administrative Procedure Act claim doesn’t accrue until the specific plaintiff is injured, not when the rule was issued. A business that didn’t exist when a federal rule was promulgated gets a fresh six-year window running from the day the rule first injures it. Municipalities inherit this vulnerability whenever an ordinance incorporates a federal definition directly, was put in place as a condition of federal funding, or cross-references a federal standard that can later change — what I’ve elsewhere called interpretive dependence: Reliance, for an ordinance’s own validity, on borrowed statutory language the municipality doesn’t control.
This exposure is real but not automatic. Standing, ripeness, and statute-specific repose periods remain intact; Corner Post did not disturb them. The concern isn’t that every old ordinance will be challenged. It’s that ordinances depending on a challengeable federal action now carry a litigation tail that didn’t exist before July 2024.
Corner Post isn’t the only way a federal predicate can fail—just the mechanism that makes the failure recurring. Center for Biological Diversity v. Zeldin shows the one-time version: A federal district court vacated the Environmental Protection Agency’s (EPA) approval of Florida’s Clean Water Act Section 404 permitting program in February 2024, permitting authority reverted to the Army Corps of Engineers that spring after the court denied Florida’s stay motions, and the D.C. Circuit affirmed in March 2026. Florida municipalities that had built their development calendars around that program absorbed the disruption without ever litigating the underlying question themselves—the program’s own federal authorization was found deficient in a case they were never party to.
Municipal legality can therefore turn on litigation the municipality never joined. Corner Post makes that exposure recurring rather than exceptional, and that shift changes what municipal legal risk management has to look like: It can no longer end when an ordinance is adopted. It has to become cyclical.
I authored a judicial impact assessment framework that builds in periodic reassessment through defined review triggers. One of those triggers is a new court decision touching an ordinance’s litigation history. For a federally dependent ordinance, Corner Post is why that trigger never really closes—a clean litigation record no longer means the ordinance is safe, only that the plaintiff who will eventually test it hasn’t shown up yet.
Consider a municipal stormwater ordinance enacted in 2015 under an EPA reading of “waters of the United States”—a term Sackett v. EPA narrowed the year before Loper Bright, and one four of the nine justices would still draw differently. This isn’t hypothetical: Permits for municipal separate storm sewer systems, known as MS4s, routinely require municipalities to put local stormwater ordinances in place tied to that federal definition, as Massachusetts’ small-MS4 permit does. A business opening in 2027 may have until 2033 to challenge the underlying interpretation, applying Loper Bright review to a rule written for a deference era. If that challenge succeeds, the ordinance may lose the federal foundation it depended on — though one with an independent, nonfederal basis could survive regardless.
Three responses are worth considering. First, audit existing ordinances for federal predicate dependency: Direct incorporation of a federal definition, enactment as a funding condition, or cross-reference to a standard that could later change. Second, fold monitoring of the relevant circuit’s docket into the municipality’s existing legal review, so a credible challenge automatically triggers reassessment; municipalities without capacity for continuous tracking can capture most of the benefit with an annual check. Third, where review surfaces genuine risk, consider amending or reenacting the ordinance with updated, independent findings rather than retroactively supplementing the original record — courts may treat that as post hoc rationalization. A targeted amendment can moot or narrow a challenge, but it creates a reviewable action of its own, so the trade-off deserves deliberate weighing, not assumption.
Corner Post didn’t destroy regulatory finality—it redefined it, turning the litigation tail on federally dependent ordinances from a finite concern into an enduring one. Finality now runs from each plaintiff’s injury, not the rule’s promulgation. The question is no longer whether an ordinance was legally sound when adopted. It’s whether the federal foundation beneath it will still exist when the next newly injured plaintiff gets standing to test it. Municipal resilience now depends not only on drafting ordinances well, but on continually reassessing the federal ground they stand on.
Oksana Manko is a legal scholar specializing in administrative and local governance law and the author of the judicial impact assessment conceptual framework, referred to in this article.
