The Federal Energy Regulatory Commission's Order No. 1920 is, on paper, the most consequential transmission rule in a generation: it requires the nation's grid operators to plan the high-voltage system at least 20 years out, to account for the resources and demand that are actually coming, and to figure out in advance how the cost of new lines will be divided. The hard part has always been that last clause. Planning a line is an engineering exercise; deciding who pays for it is a political one. A June 9, 2026 notice in FERC Docket No. RM21-17-000 shows just how political, as PJM Interconnection's transmission owners and the states they serve once again asked for more runway before committing to a cost-allocation formula.
According to the notice, on June 4, 2026 the PJM Area Relevant State Entities Committee, known as PARSEC, and the PJM Transmission Owners filed a joint motion making two requests. PARSEC asked the Commission to extend the "Engagement Period" during which states and utilities are supposed to hash out an approach. The PJM Transmission Owners asked for a 60-day extension, until August 11, 2026, of the deadline for filing their portion of the Order No. 1920 regional compliance package. The parties told FERC that an additional extension, paired with the chance to use mediation, was appropriate given the difficulty of designing what the filing calls an "ex ante Long-Term Regional Transmission Cost Allocation Method" for a region as diverse as PJM, which spans 13 states and the District of Columbia.
Why cost allocation is the sticking point
"Ex ante" is the operative phrase. FERC's policy preference, embedded in Order 1920, is that the rules for splitting transmission costs should be settled before the lines are built, not litigated afterward, so that planners can compare project benefits against a known formula. The trouble is that the benefits of a long-distance transmission line are notoriously unequal and contested. A project that improves reliability in one state may chiefly lower energy prices in another, while a third state worries it is subsidizing development it did not request. PARSEC exists precisely because PJM's footprint contains such a wide spread of state energy policies, from heavy offshore-wind commitments on the Atlantic coast to coal- and gas-heavy interior states, and each of those states regulates retail rates and sites transmission within its own borders.
That is the meaning behind the footnote in the notice describing PARSEC as a group of "Relevant State Entities" responsible for electric utility regulation or for siting electric transmission facilities within PJM, a definition drawn directly from Order Nos. 1920 and 1920-A. By giving states a formal seat through the relevant-state-entity construct, FERC tried to make cost allocation collaborative rather than imposed. The cost of that collaboration is time: consensus among more than a dozen sovereigns moves slowly, and the June filing is essentially the parties telling the Commission they would rather mediate than litigate a method that none of them fully endorses.
An order that has already been reheard twice
The procedural history embedded in the notice underscores how contested the underlying rule is. The Commission cites Order No. 1920, issued at 187 FERC paragraph 61,068, followed by an order on rehearing, Order No. 1920-A at 189 FERC paragraph 61,126 in 2024, and then a further order on rehearing, Order No. 1920-B at 191 FERC paragraph 61,026 in 2025. A major rule drawing two successive rehearing orders signals that the affected parties pushed back hard on multiple fronts, and that the Commission itself refined the requirements as the objections came in. Each of those revisions reshaped exactly what regions like PJM must file, which is part of why the compliance timeline keeps stretching.
The mechanics of this particular extension are worth noting because they reveal how live the dispute is. The notice set a short fuse on responses: answers to the joint motion had to be filed by 5:00 p.m. Eastern Time on June 9, 2026, the same day the notice published. That compressed window is typical when a deadline is imminent and the Commission needs to rule quickly on whether to grant relief. The requested new deadline, August 11, 2026, would push PJM's transmission-owner compliance filing into late summer, well after several of the original Order 1920 milestones the Commission set when it issued the rule.
What it means for the grid build-out
For anyone tracking whether the United States can actually build the transmission the energy transition requires, this docket is a leading indicator. Order 1920 was supposed to break the logjam that has left interconnection queues clogged and large regional lines unbuilt for years. But the rule only works if regions convert its planning mandates into enforceable tariff language, and that conversion runs straight through the cost-allocation question. Every extension in RM21-17 is a reminder that the binding constraint on grid expansion is increasingly institutional rather than physical. The wind, solar, storage, and data-center load are all lining up; what is missing is an agreed answer to who pays for the wires that connect them.
The choice to pursue mediation rather than simply file a contested method is also telling. A mediated outcome that the states and transmission owners both accept is far more durable than one FERC imposes over objection, because it is less likely to be appealed and unwound. If PARSEC and the PJM Transmission Owners can reach a genuine consensus method by August, it could become a template other regions study as they work through their own Order 1920 compliance. If they cannot, the Commission will eventually have to decide the allocation itself, and the resulting order would almost certainly head to the courts.
For now, the August 11, 2026 date is the one to watch. It is not the end of the Order 1920 story in PJM so much as the next checkpoint in a slow, high-stakes negotiation over the financial architecture of the largest electricity market in North America. The lines that get planned under this framework will carry power for half a century; the formula being argued over this summer will decide whose ratepayers fund them.