How a Law Becomes a Rule
Agencies, such as the SEC and the FDA, write most of the rules that govern the United States. Congressional statutes and executive orders, though often lengthy, rarely define clear rules; instead they empower agencies to fill in the specifics. For example, the Affordable Care Act's contraceptive mandate says nothing about birth control, only requiring insurance companies to offer preventive care. The act left the definition of preventive care to the Health Resources and Services Administration (HRSA), which determined it included contraception. This determination led to a decade of legal fights and multiple Supreme Court cases. But unlike statutes and executive orders, agency rules have open comment windows, and agencies are legally required to respond, offering non-politicians a chance to influence policy.
Writing the Rules #
Agencies write thousands of rules per year. As of this writing (June 2026), 1,118 rules have open comment windows on the Federal Register. Several triggers may drive agencies to create new rules, such as the president signing a congressional bill into law. Congressional statutes largely cover funding, broad definitional and legal matters, and agency responsibilities. Agencies then define specifics to create enforceable rules. The president can sway these agencies by appointing their heads, subject to Senate confirmation. The president can freely fire the heads of agencies that fall under the Executive Branch, such as the FDA and Housing and Urban Development (HUD). But for independent agencies, such as the SEC and the Federal Reserve, the president cannot fire the heads without cause (pending the Trump v. Cook ruling).
Other mechanisms can also drive agencies to create new rules. The president, via executive order or through the Office of Management and Budget (OMB), can direct agencies to write new rules. Agencies may also write new rules in response to a lawsuit or court ruling. Finally, agencies have authority to write new rules without any prodding by Congress or the president. For example, the FCC wrote net neutrality rules without clear presidential, congressional, or judicial initiative.
After deciding to write a rule, agencies typically consult outside stakeholders and lobbyists lawyers.[1] These outside interests seek this consultative role, with one estimate finding they spend 2.5 to 20 times as much money lobbying agencies as they do lobbying Congress. Agencies, however, argue businesses and outside interests can help them better understand the rule's feasibility.
Challenging the Rules #
The president has the strongest check. After a rule is drafted, it typically goes through the Office of Information and Regulatory Affairs (OIRA), which the president controls. Historically, OIRA only reviewed rules of Executive Branch agencies, but a 2025 executive order required independent agencies to submit "significant rules" to OIRA for review. OIRA can pressure the agency to change the rule, or perpetually return it to the agency for reconsideration, giving the Executive Branch an effective veto.
Congress has less control than the president over agency rules. Although the Congressional Review Act (CRA) allows Congress to veto a rule, the president can veto Congress' veto. More typically, a congressional majority may halt the funding an agency needs to implement a rule by attaching a regulatory limitation rider to appropriations bills. Although the president can veto a limitation rider, the veto would apply to the entire appropriations bill, thereby thwarting policies the president may want to pass. Since limitation riders typically conflict with the president's agenda, they are more common under divided government.
Non-governmental parties can also challenge a rule before it's finalized. The Administrative Procedure Act (APA) requires agencies to post their initial draft and hold an open comment period. Agencies must respond to all substantive comments.[2] Courts have long held that rules can be thrown out as being "arbitrary and capricious" if agencies fail to respond to these comments. The Supreme Court went further in the 2015 Perez v. Mortgage Bankers Ass'n, determining that the APA required agencies to respond to comments as a procedural duty. Agencies typically respond to these comments in the preamble section of the final rule.
Historically, Chevron deference and similar deference doctrines held that judges should defer to agency discretion, thereby making legal challenges difficult. But the Supreme Court overturned Chevron deference in the 2024 Loper Bright Enterprises v. Raimondo and Relentless Inc. v. Department of Commerce cases, which may lead to more litigation for the agencies. Even before this decision, courts didn't automatically defer to agencies. One 2019 study found that agencies won just over half of their rulemaking lawsuits between 1999 and 2012. But it also noted that challenges against an agency rarely made it to court, likely due to the deference filter. Because this filter no longer holds, we are likely to see more challenges against the agencies.
Although we often pay more attention to congressional and electoral fights, agencies write around 90 percent of the rules that regulate US citizens and businesses. Furthermore, obscure officials in agencies like the Treasury Department design and implement US foreign policy. Sophisticated interests acknowledge this, as most of their lobbying budgets target regulators. But unlike congressional bills and executive orders, agency rules typically have public comment windows with a requirement to respond, giving non-politicians some say in the matter.