In the case of Perez v. Mortgage Bankers Association, the U.S. Supreme Court ruled in 2014 that federal agencies do not have to go through a formal rulemaking process before making significant changes to rules interpreting their own regulations. The court's decision overturned a previous ruling by the D.C. Circuit Court of Appeals which had held that any change in an agency’s interpretive rule must be subjected to notice-and-comment procedures under the Administrative Procedure Act (APA). The Supreme Court disagreed with this interpretation and stated that it was inconsistent with both APA text and longstanding practices of federal agencies, thereby allowing them more flexibility in changing their interpretations without public input or scrutiny.

In the dissenting opinion for Perez v. Mortgage Bankers Association, Justice Scalia argued that the Court's decision to allow federal agencies to interpret their own regulations without judicial review was a violation of separation of powers principles. He contended that this practice allowed executive agencies to both write and interpret laws, which is contrary to the Constitution's design where Congress writes laws and courts interpret them. Furthermore, he criticized what he saw as an excessive deference by courts towards administrative interpretations under Auer v Robbins (1997), arguing it undermines legal predictability and allows agencies too much leeway in shaping policy through reinterpretation of rules rather than going through proper rulemaking procedures. In his view, such unchecked power could lead to arbitrary government action or favoritism towards certain groups.