WASHINGTON — The four largest U.S. hyperscalers filed initial comments on Treasury’s proposed grid-impact disclosure rule Friday afternoon, with positions tracking the broad outlines of the May fourteenth notice of proposed rulemaking but registering specific objections on the rule’s multi-tenant treatment, curtailment-cooperation provisions, and the calibration of the 25,000-chip threshold.

The comment filings, which arrived in the Federal eRulemaking Portal between two and four p.m. Eastern, were the first substantive industry responses to the rule since its publication twenty-four hours earlier. Trade associations and individual companies had until July 28 to file comments under the proposal’s seventy-five-day comment window, but the four largest operators had signaled in advance that they intended to file early comments to set the framework for subsequent industry engagement.

The comments collectively endorsed the rule’s general approach but identified what one filing characterized as “calibration issues that would substantially affect the rule’s practical workability.” All four filings raised the question of multi-tenant facilities — physical buildings housing AI compute capacity from multiple operators — which the rule’s current language treats as triggering the disclosure threshold based on aggregate facility-level capacity rather than per-operator capacity within the facility.

The multi-tenant question matters because the largest hyperscalers operate substantial third-party hosting arrangements alongside their own training facilities, and the rule’s current language would impose disclosure obligations on those third-party arrangements at thresholds the operators say do not correspond to the rule’s stated policy rationale. One filing proposed an “operational unity” test that would treat workloads as separate for threshold purposes if they were operated under separate management, separate scheduling systems, and separate customer contracts.

The curtailment-cooperation provisions drew particularly extensive commentary. The rule’s current language would require facility operators to commit to curtailment of non-critical workload during grid-emergency events, with an exemption for inference traffic deemed time-sensitive by the facility’s principal customers. The filings all argued that the exemption framework needed to be expanded to cover broader categories of customer-facing workload and to provide for compensation arrangements when curtailment imposes costs on customers.

A senior Treasury official, asked Friday afternoon about the early comment filings, said the department’s review was “fully open” to substantive engagement with the questions the filings raised and that the rulemaking process had been designed to allow for revision of the proposal in response to comments. The official emphasized that the disclosure framework’s core policy rationale — providing federal-level visibility into the largest tier of AI compute facilities — was non-negotiable, but that the operational implementation could be calibrated based on substantive input.

The Federal Energy Regulatory Commission, which would house the proposal’s principal disclosure channel if the rule is finalized, issued a brief statement Friday afternoon noting that it had received the comment filings and would coordinate with Treasury on technical questions raised by the filings. FERC Chairman Willie Phillips, in an unrelated speech in Houston Friday morning, had emphasized that the commission’s role under the proposal would be focused on “the engineering questions that the disclosure framework will surface, not on broader policy debates about AI infrastructure deployment.”

The Information Technology Industry Council, the principal trade association representing the affected hyperscalers, filed a separate comment Friday afternoon that consolidated the four operators’ shared positions and added several additional industry-level concerns. ITI’s comment characterized the proposal’s threshold calibration as “approximately appropriate” but called for explicit guidance on the treatment of capacity additions that bring facilities marginally above the 25,000-chip or 200-megawatt thresholds.

A senior official at one of the four hyperscalers, contacted Friday afternoon, said the filing had been prepared in close coordination with the company’s compliance, government affairs, and infrastructure-operations teams over the past week. The official said the early filing was intended to “establish a constructive substantive baseline” for the comment period rather than to mount substantive opposition to the rule, which the company supported in general framework.

The Hennessey-Blackburn AI Transparency and Grid Impact Act, which had been introduced in the Senate last week, is expected to receive its first Commerce Committee markup in early June. A senior Senate Commerce Committee staffer, contacted Friday, said the committee’s review of the Treasury rulemaking and the legislative drafting would proceed “in parallel and in coordination,” with the goal of ensuring that the statutory framework complements rather than duplicates the administrative rule.

State-level engagement with the Treasury proposal has been particularly active in California, where the Durazo data-center moratorium bill cleared the Senate Energy, Utilities and Communications Committee on May thirteenth with a narrowed 200-megawatt threshold that aligns with the Treasury proposal’s federal threshold. The California Public Utilities Commission filed an observer comment Friday afternoon noting the alignment and offering to share state-level implementation experience as the federal rulemaking proceeds.

The Frontier Model Assurance Council, the industry-funded body established under the May eighth voluntary disclosure framework, did not file a comment Friday but is expected to file during the second week of the comment window. The Council’s interim director, Pavithra Ramaswamy, in a Tuesday interview, had characterized the Treasury proposal as “the infrastructure-side counterpart to what we are doing on the model-release side” and indicated that the Council’s comment would focus on the operational interfaces between the two frameworks.

The next set of substantive comment filings is expected during the third week of the comment window, with consumer-facing technology trade associations, environmental groups, and state-level energy regulators anticipated to file substantive comments before the end of June.