The order accepts PJM's proposed revisions to Schedule 12-Appendix A of the PJM Open Access Transmission Tariff (Tariff). These revisions establish who pays for transmission additions and modifications approved in PJM's 2026 Regional Transmission Expansion Plan (RTEP), which the PJM Board of Managers approved on February 12, 2026. The revised cost assignments take effect June 14, 2026.

PJM's 2026 RTEP Adds 358 Transmission Projects Across Its 13-State Footprint

The filing covers a substantial range of project types. PJM included cost responsibility assignments for 78 new regional or necessary lower-voltage facilities addressing reliability needs, 87 lower-voltage reliability upgrades estimated to cost more than $5 million each, and 125 smaller reliability enhancements that fall below that threshold. The filing also covers 68 local reliability projects on transmission lines operating at or below 200 kilovolts, 26 individual circuit breaker replacements or additions, and four economic transmission projects tied to reducing load energy costs in specific zones.

Cost allocation across this project set follows a hybrid methodology. For regional and necessary lower-voltage facilities, PJM splits responsibility equally: 50% distributed across the system using a load-ratio share method, and 50% assigned to specific customers based on power-flow modeling known as the solution-based distribution factor (DFAX) method. Lower-voltage projects use DFAX alone. Smaller reliability upgrades and local enhancements are allocated 100% to the transmission zone where the facility is located.

FERC Directs PJM to File Updated Cost Allocations Within 30 Days

FERC accepted the tariff revisions but also issued a directive requiring PJM to submit a compliance filing within 30 days of the May 15 order. The requirement stems from a separate March 6, 2026 FERC order in a Consolidated Edison proceeding that directed PJM to eliminate its de minimis threshold exemption from cost responsibility calculations. That threshold had previously excluded very small cost assignments from being distributed, which simplified administration but effectively shifted a portion of project costs onto other customers. PJM acknowledged in its filing that the current cost assignments were calculated under the old threshold and may need revision once the compliance filing is complete.

The interaction between these two proceedings means the final cost responsibility picture for the February 2026 RTEP projects is not fully settled. Customers in PJM zones should expect a follow-on filing from PJM before mid-June that could adjust individual cost shares, depending on how the de minimis elimination is applied retroactively to the current project set.

What This Means for Large Commercial and Industrial Customers in PJM Zones

Transmission expansion costs in PJM flow through to large commercial and industrial customers via transmission enhancement charges reflected in utility rates and transmission service agreements. The scale of the current RTEP buildout reflects the demand growth pressures that PJM has documented repeatedly over the past 18 months. New interconnection requests tied to data center expansion and electrification are straining existing infrastructure across Maryland, Virginia, Ohio, Pennsylvania, and Illinois, all states with significant PJM service territory. Projects approved in this RTEP cycle represent part of the infrastructure response to those demands, with cost responsibilities now formally assigned across the region's utilities and large transmission customers.