Recent Rulemakings Reviewed is a monthly quantitative snapshot of federal regulatory activity, drawn from FRTracker—a platform that ingests Federal Register documents and decomposes binding rules into structured “obligations.”

An “obligation” in this dataset is a single regulated duty extracted from a rule’s text, comprised of: an actor (e.g., operator, employer, importer), a deontic modal (must, shall, may not), and an action.

Each issue of Recent Rulemakings Reviewed will present the preceding month’s key numbers, some developments worth watching, and links for readers who want to dig deeper.

The numbers

• Documents published (excluding presidential documents): 2,268
  • vs April 2026: 2,143
  • vs May 2025: 2,254
• Final rules: 252
  • vs April 2026: 253
  • vs May 2025: 223
• Proposed rules: 176
  • vs April 2026: 169
  • vs May 2025: 175
• Rules flagged significant in Federal Register metadata: 34
  • vs April 2026: 33
  • vs May 2025: 40
• Proposed→final pairs detected: 3; net obligation change +15 (33 added, 18 removed)
• Comment periods closed last month: 644
• Compliance obligations extracted from last month’s publications: 2,659

Three developments worth watching

1. The SEC moves to make capital-raising easier.

Within a single week, the Commission issued two significant proposals. Enhancement of Emerging Growth Company Accommodations and Simplification of Filer Status (proposed May 21; 98 obligations extracted) would widen the on-ramp for newer public companies, and Registered Offering Reform (proposed May 26; 67 obligations) revisits the mechanics of registered securities offerings. Both are proposals, open for comment, and together they may signal a deregulatory tilt toward capital formation from one of the month’s busiest agencies.

Primary source: Federal Register (2026-10222, 2026-10373) · FRTracker analysis

2. EPA proposes to ease PFAS drinking-water rules.

On May 20, the agency proposed Extending the Compliance Deadline for the PFOA and PFOS Maximum Contaminant Levels, which would keep the landmark “forever chemicals” limits in place but push back the timeline by which water systems must meet them—and, in a companion proposal the same day, would rescind the regulatory determinations underpinning the federal limits for several additional PFAS compounds. For water utilities that had begun building compliance programs around the original deadlines, the practical question for PFOA and PFOS is no longer what to do but when—while for the other compounds in the companion proposal, it is whether a federal obligation survives at all.

Primary source: Federal Register (2026-10086, 2026-10085) · FRTracker analysis

3. Interior unwinds a public-lands conservation rule.

On May 12, the Bureau of Land Management finalized the Rescission of the Conservation and Landscape Health Rule—rolling back the 2024 “Public Lands Rule”—while simultaneously proposing a Revision of Regulations for Grazing Administration (a substantial 139 obligations extracted). One action is done; the other is open for comment. Read together, they mark a reorientation of how the federal government balances conservation and use on the public range.

Primary source: Federal Register (2026-09386, 2026-09387) · FRTracker analysis

Remarkable Rulemakings

A few of the ways the month stood out once you count obligations instead of documents—the outliers and inversions that a raw filing tally might otherwise hide.

The rule with the most obligations carried no “significant” flag. The Nuclear Regulatory Commission’s Licensing Requirements for Microreactors and Other Reactors With Comparable Risk Profiles (proposed May 1) yielded 625 extracted obligations across a 139-page proposal—more than twice the next-highest count of any rule that month—yet it carries no OIRA significance designation under E.O. 12866. Counting duties surfaces a regulatory heavyweight that the significance label passes over.

The busiest agency was not the most demanding. The Commerce Department led May on document count—282 filings—but those yielded just 145 extracted obligations, eighth among agencies. The obligation lead went instead to the NRC (740, most of it the microreactor proposal above) and the Interior Department (409, from 140 documents). Raw filing volume and regulatory weight are not the same thing.

Agencies finalized more, proposed about the same, and flagged fewer as major. Against May 2025, final rules rose 13 percent (223 to 252) while proposed rules held essentially flat (175 to 176) and significant designations fell (40 to 34). The month reads less like a wave of new initiatives than like a stretch spent finalizing rules already in the pipeline, few of them designated major.

Further reading

Most active agencies last month (number = Federal Register documents published):

• Commerce Department (282 docs)
• Homeland Security Department (238 docs)
• Securities and Exchange Commission (224 docs)
• Transportation Department (195 docs)
• Health and Human Services Department (192 docs)

Significant rules published. OIRA flagged these rules as significant under E.O. 12866 §3(f). We show the five with the largest extracted obligation count; ordering is ours, designation is theirs.

• Revision of Regulations for Grazing Administration, Exclusive of Alaska — Interior Department (139 obligations)
• Enhancement of Emerging Growth Company Accommodations and Simplification of Filer Status for Reporting Companies — Securities and Exchange Commission (98 obligations)
• Small Business Lending Under the Equal Credit Opportunity Act (Regulation B) — Consumer Financial Protection Bureau (98 obligations)
• Patient Protection and Affordable Care Act, HHS Notice of Benefit and Payment Parameters for 2027; and Basic Health Program — Health and Human Services Department (74 obligations)
• Registered Offering Reform — Securities and Exchange Commission (67 obligations)

Rules that took effect. OIRA-significant rules (E.O. 12866 §3(f) designation) are listed first, then ordered by extracted obligation count.

• Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Large Municipal Waste Combustors Voluntary Remand Response and Five-Year Review — Environmental Protection Agency (239 obligations) · significant
• Administrative Rulemaking, Guidance, and Enforcement Procedures — Transportation Department (96 obligations) · significant
• Generic Environmental Impact Statement for Licensing of New Nuclear Reactors — Nuclear Regulatory Commission (36 obligations) · significant
• Practices Before the Department of the Interior — Interior Department (10 obligations) · significant
• Defense Federal Acquisition Regulation Supplement: Disclosure of Greenhouse Gas Emissions — Defense Department (3 obligations) · significant
• Pipeline Safety: Class Location Change Requirements; Correction — Transportation Department (2 obligations) · significant
• Department of Labor Federal Civil Penalties Inflation Adjustment Act Annual Adjustments for 2026 — Labor Department (1 obligation) · significant
• Administrative Simplification; Adoption of Standards for Health Care Claims Attachments Transactions and Electronic Signatures — Health and Human Services Department (1 obligation) · significant

(Three additional significant rules took effect in May with no obligations extracted from their text: a terminology technical amendment, a critical-habitat designation, and an appliance-standards exemption.)

For readers who want the underlying dataset: the full monthly snapshot is at frtracker.app/monthly/2026-05, with methodology at frtracker.app/methodology.

Andrew Leahey is an Assistant Teaching Professor of Law at Drexel Kline School of Law.