PJM's curtailment hierarchy is the sharpest instrument in the tariff. Large loads without behind-the-meter generation face the deepest cuts — data centers sit at the top of the list, ahead of residential and commercial customers, when supply tightens. The hierarchy's operational logic is simple: the largest loads with the least self-sufficiency are curtailed first. [1]

But the board letter's most significant phrase is not about curtailment. It is about cost allocation. The filing states that "state action is essential" to determine how the costs of reliability backstop procurement are distributed — whether they fall on the data centers that triggered them, on all ratepayers, or on some hybrid. The phrase is a signal, not a conclusion. It tells state regulators that PJM will not allocate the costs unilaterally, and it tells data centers that the tariff they face may differ by state. [1]

Maryland's Office of People's Counsel has already challenged $2 billion in data-center-driven transmission costs. Pennsylvania's governor filed a FERC complaint. The tariff enters that fight with a concrete framework: the curtailment hierarchy assigns the reliability obligation, and the "state action is essential" language frames the cost question as a political decision, not a market outcome. [1]

The DOE's emergency orders in June and July — authorizing PJM to curtail facilities above 50 MW — established the curtailment hierarchy as a federal operational tool. But the cost-allocation question remains unresolved. The September-October auction window will set the next capacity price. The state regulatory process will determine who pays for the reliability that price purchases. The two records are separate, and the gap between them is where the tariff's real consequences will land.

For the paper, the "state action is essential" line is the divergence. MSM covered the curtailment headline. X debated whether data centers should be curtailed at all. The cost-allocation detail — the question of who bears the financial burden when the grid tightens — was the part that matters most to ratepayers, and it was the part that both coverage streams buried.