The Federal Energy Regulatory Commission on June 18, 2026, launched targeted enforcement action ordering regional transmission organizations and independent system operators to justify or reform their tariffs for connecting data centers and other large energy users to the interstate grid — the sharpest regulatory move yet in a multi-year effort to reconcile surging AI infrastructure demand with transmission capacity that was never designed for it.

The order lands at a moment when FERC's pipeline of activity on large-load interconnection has been building in sequence. In February 2025, the commission voted unanimously to open a formal review of co-location — the practice of siting large loads, including AI-enabled data centers, directly at generation facilities to sidestep congested transmission queues. That review escalated: by October 2025, the Department of Energy had directed FERC under Section 403 of the Federal Power Act to accelerate data center interconnection, which opened docket RM26-4 in January 2026 addressing the technical and tariff rules for connecting large loads to interstate transmission.

In December 2025, FERC moved from study to directive, ordering PJM Interconnection — the RTO covering roughly a third of U.S. electricity consumption — to create new rules and an expedited interconnection pathway for large loads, with initial tariff briefs due February 16, 2026. Utility Dive reported in April 2026 that FERC had followed through with specific changes to PJM's interconnection study process. In that same month, FERC committed publicly to issuing a final rule under RM26-4 by June 2026 — the deadline it has now met with the June 18 action.

What the June Order Actually Does

The June action targets tariff structures across RTOs and ISOs, not just PJM. Grid operators must either demonstrate that existing tariff terms are just and reasonable for large-load applicants or propose reforms. The practical effect is to put every regional operator on notice that the legacy generator-oriented queue process — built over decades around wind farms and gas peakers, not hundred-megawatt campus loads — faces mandatory scrutiny.

FERC is also deploying automation and AI tools within its own interconnection study workflow, with a stated goal of fast-tracking more than 60 interconnection permits by end of 2026, according to the commission's January 2026 operational outlook. That's notable for its self-referential quality: the agency regulating AI infrastructure build-out is using AI to process the paperwork that build-out generates.

The Underlying Engineering Tension

The core problem is straightforward to state and hard to solve. A hyperscale AI inference or training campus draws 100–500 MW continuously, with a load profile far flatter and more persistent than most generation sources were sized against. Plugging that kind of load into a substation that feeds a regional transmission node can create fault-current, stability, and capacity obligations that ripple through the interconnection queue for projects that filed years earlier. Co-location at generation sites — putting the data center behind the generator's point of common coupling — has emerged as one workaround, but it raises its own set of FERC jurisdictional questions about whether energy consumed on-site before it reaches the interstate system is subject to open-access tariff requirements.

That jurisdictional ambiguity is precisely what the 2025 co-location review was designed to address, and it feeds directly into the tariff-reform orders now reaching RTOs.

Worth flagging: the pace of regulatory action here is genuinely unusual for FERC, which historically moves on multi-year rulemaking timelines. The sequence from unanimous vote to DOE directive to formal docket to RTO-specific order to nationwide tariff-reform action across roughly 16 months reflects political and commercial pressure that has few recent analogues in transmission policy. Whether the resulting rule structures will be durable — or will require further revision as load profiles and co-location architectures continue to evolve — is an open question the commission itself has acknowledged by building review mechanisms into the RM26-4 docket.

For engineers managing interconnection queues, the practical implication is that the rules of engagement are changing on an accelerated schedule. Tariff filings that looked settled six months ago may be reformulated before year-end. For hyperscalers and colocation operators with interconnection applications in flight, the directional signal from FERC is clear enough: the commission is trading procedural caution for speed, and the RTOs will be compelled to follow.