Idaho eliminated 49.1% of its regulatory code between 2018 and 2026, cutting 4,201 pages through a systematic overhaul known as Zero-Based Regulation, according to a Manhattan Institute report published in 2026. The state achieved reductions every year across that span by flipping the traditional review process: instead of asking which rules should be removed, agencies had to justify which provisions deserved to remain. The approach combined a one-time regulatory reset in 2019 with a recurring five-year review cycle that concluded in 2026, producing what the report describes as one of the most dramatic state-level regulatory reductions in recent memory.
The initial reset, which the state called "pressure washing," removed 2,176 pages or 25.4% of baseline regulatory volume when the legislature declined to extend existing rules and Governor Brad Little directed agencies to republish only necessary provisions as temporary rules. But the subsequent "spring cleaning" phase—a staggered review of every rule chapter from 2021 through 2025—cut an additional 2,025 pages, or 23.7% of the baseline. All 48 agencies with rules at the 2018 baseline reduced their regulatory footprint, with cuts ranging from 13% at the secretary of state to 100% at six agencies. Agencies with baseline volumes of 20 pages or fewer averaged 62% reductions, while those with 21 to 100 pages cut 61% on average. The state's largest agencies, with more than 500 pages at baseline, averaged 49% cuts driven largely by intensive focus on occupational licensing and health services.
The recurring review phase sustained momentum despite personnel changes, with annual regulatory volume declining between 3.4% and 12.5% each year throughout the cycle. Agencies took an average of 5.5 years to reach their lowest regulatory volume, and that timeline lengthened sharply with baseline size—agencies starting with more than 500 pages needed an average of eight years and were still cutting regulations in the final year. Only four agencies showed any growth from their post-2018 low points, adding a combined 12 pages or 2.2% as of 2026. The Division of Occupational and Professional Licenses, created in 2020 by consolidating 11 separate licensing agencies, became the strongest large-agency performer, eliminating 724 pages or 71% of its baseline and removing barriers like mandatory state-specific law exams for non-legal professions and unnecessary continuing-education requirements for endorsement applicants.
The report argues that the initial purge broke the inertia of accumulated rules but that the recurring review phase uncovered deeper, more consequential reforms by forcing agencies to examine legal authority, necessity, costs, benefits, and whether less restrictive alternatives existed. Pressure washing targeted obsolete programs, stale cross-references, and provisions that wouldn't be adopted today—rules governing female kickboxing attire, a snail species not found in Idaho, and deputy veterinarian dress codes all expired. Spring cleaning required agencies to ask whether facially plausible rules were more burdensome than necessary, leading to changes like allowing pharmacists to independently diagnose conditions and write prescriptions, removing caps on physician assistants per physician, and consolidating 17 commercial-motor-vehicle permits into eight. The authors note that statutory mandates set the ceiling on agency reform because legislatures often pass broad policy goals and authorize agencies to fill in details, creating what they call "a pipeline for future regulatory growth." Complementary reforms helped sustain momentum: central oversight through the Division of Financial Management, legislative review requiring two-chamber approval of all regulations, chapter-level regulatory budgets, and moving stable requirements from administrative rules into statute while rescinding the agency's authority to recreate them.
Idaho has now shifted from a five-year executive-driven cycle to a statutory eight-year review of rule chapters, testing whether the discipline can outlast changes in personnel and politics. The report concludes that durable reform requires resetting the inherited baseline, adopting a staggered review schedule that gives complex agencies time to work, pairing reductions in existing rules with controls on future additions, and examining the statutory delegations that feed the code. States must address both the stock of existing regulations and the flow of new ones, because changing the rule-review process while never examining the legal authorities behind it solves only half the problem. If the recurring discipline survives, the authors write, Idaho's legacy won't just be cutting roughly half its regulatory code—it'll be changing the governing presumption so that rules don't persist merely because they already exist.