For years, courts upheld controversial statutory interpretations by agencies under the Chevron doctrine. That doctrine instructed courts to defer to agency interpretations when laws were unclear. But in 2024, Loper Bright Enterprises v. Raimondo overturned Chevron and returned the responsibility of deciding what the law means to the courts. Nonetheless, old doctrines have a habit of returning under new names. In Lesko v. U.S., the Federal Circuit invoked Loper Bright itself to revive the premise that statutory silence can itself justify an agency’s interpretive power.

The Office of Personnel Management’s (OPM’s) attempt to assume interpretive power came in the context of the COVID-19 pandemic. That crisis placed extraordinary demands on the nation’s hospitals, and federal nurses bore much of that burden. When supervisors directed more than a thousand nurses to remain beyond their scheduled shifts, the nurses did so without hesitation. However, their overtime went uncompensated for one reason alone: their orders had never been put in writing. The Federal Employees Pay Act (FEPA) promises overtime pay for work that is “officially ordered or approved.” The law says nothing about a writing requirement. But OPM added one anyway, relying on its general regulatory authority to declare that overtime may be approved “only in writing”—and argued that, therefore, the nurses’ overtime should go unpaid.

In ruling against the nurses, the Federal Circuit relied on a few innocuous words from Loper Bright itself: Congress may allow agencies to “fill up the details” of a law. Because FEPA did not specify the formalities for approving overtime, and because OPM had general authority to issue rules administering the subchapter, the court held that OPM could require overtime approval to be in writing.

Cato has filed a brief supporting the nurses. Our brief argues that the Federal Circuit’s reasoning fails for three reasons:

First, silence is not delegation. In the cases that introduced the phrase “fill up the details,” Congress expressly identified the subject another body could regulate. Congress could easily have written “in such a manner as OPM shall prescribe,” but it did not. Statutory silence does not show that Congress left a question open for an agency to resolve. 

Second, a writing requirement is not a permissible “detail.” Details help carry out a law; they do not rewrite it. When a supervisor tells a nurse to stay late, the overtime has been officially ordered in the ordinary sense of those words. And if an agency can add one condition, it can add others. Detail-filling authority can give an agency some discretion in choosing the means to implement a directive enacted by Congress, but it cannot allow the agency to add a new substantive condition to change when a statutory right attaches. 

Third, reading an agency’s authority to “fill up the details” too broadly would once again allow agencies to override the courts. Under Chevron, an agency could adopt its own interpretation of a law and displace a court’s earlier reading without Congress changing a single word. This case shows why that is dangerous: In 1956, a federal court held that overtime approval did not need to be in writing, yet OPM’s contrary rule later prevailed. If agencies can just relabel such overrides as “details,” in practice that means that agencies can rewrite the law even after courts have said what it means.