Legislation is signed and the change it describes does not arrive. The gap is occupied by rulemaking, a procedure with its own statutory requirements and its own timetable.
Statutes describe outcomes, not procedures
Congress typically legislates in general terms, directing an agency to achieve something and leaving the technical detail to be filled in.
A law might require safer equipment or clearer disclosure without specifying the test method, the threshold or the form that must be filed.
Those specifics are written by the agency with subject expertise, and until they exist there is nothing for a regulated party to comply with.
Notice and comment is a required sequence
Administrative law obliges an agency to publish a proposed rule, accept public comment for a defined period, and respond to significant comments before issuing a final version.
Comment periods commonly run for months, and complex rules attract enormous volumes of submissions from industry, advocacy groups, state governments and individuals.
Reading and answering them is not ceremonial. An agency that ignores a substantial objection creates a vulnerability in court.
Analysis requirements add their own stages
Major rules trigger additional obligations, including economic analysis, assessment of effects on small entities, and review by the executive office before publication.
Each stage has its own queue, and a rule can sit awaiting review for a long period while other priorities move ahead of it.
Agencies also consult other departments whose jurisdictions overlap, since inconsistent rules across agencies are themselves grounds for challenge.
Litigation risk shapes the pace
Final rules are routinely challenged, and a court can send a rule back if the record is incomplete or the reasoning inadequate.
Because a remand can cost years, agencies build extensive records deliberately, documenting the evidence considered and the alternatives rejected.
Slow drafting is a defence against a slower outcome, which is a rule struck down after it has already taken effect.
Compliance dates are then set in the future
Even a published final rule usually names an effective date months or years ahead, giving affected parties time to retool, retrain or rebuild systems.
Phased schedules are common, with larger firms required to comply first and smaller ones later. The result is that the interval between a signature and a visible change is measured in years, and most of it is procedure rather than delay.