RM26-4-000 is FERC's rulemaking to standardise how loads above 20 MW connect to the US interstate transmission grid. It will bind all US RTOs/ISOs and could accelerate or ADD costs to hyperscale data-centre grid connections, with a decision due by end of June 2026.Source: FERC

When will FERC issue the large-load grid interconnection ruling?

FERC committed on 16 April 2026 to act on RM26-4-000 by end of June 2026.Source: FERC

What are the contested questions in FERC's RM26-4-000 rulemaking?

Three key disputes: whether hyperscalers can bypass standard interconnection studies; how behind-the-meter generation is treated for cost allocation; and who pays for transmission upgrades large loads trigger.Source: Mayer Brown

Background

FERC Docket RM26-4-000 is the proceeding in which the Federal Energy Regulatory Commission will set new rules for how electricity loads above 20 MW — the threshold at which most data centres sit — connect to the US interstate transmission grid. FERC committed on 16 April 2026 to act by end of June. The proceeding was opened under Section 403 of the DOE Organisation Act by Energy Secretary Chris Wright in October 2025, making it one of the few energy rulemakings in recent history explicitly directed by the executive branch.

The rulemaking will bind every RTO and ISO in the continental US, though not ERCOT. Per legal analysis from Mayer Brown, the three contested questions are: whether hyperscalers can bypass standard interconnection studies; how behind-the-meter generation is treated for grid-exit cost allocation; and who pays for transmission upgrades that large loads trigger. FERC sought a ruling that is "quick, efficient, and legally durable" — language acknowledging prior large-load reforms have been overturned in court.

The June order is the only federal-level mechanism capable of overriding the growing mosaic of municipal moratoriums and county-level restrictions on grid-connected data-centre capacity. Municipal utility boards can block hookups without FERC touching them; RM26-4-000 addresses the upstream layer — how loads access the interstate transmission system. A favourable ruling could accelerate large-load interconnection across all FERC-jurisdictional grids; an unfavourable or legally vulnerable ruling could impose new costs making US grid-connected data-centre projects even less competitive against ERCOT and foreign sites.

More questions

What is the FERC RM26-4-000 rulemaking and why does it matter for data centres?

RM26-4-000 is FERC's proceeding to standardise how new electricity loads above 20 MW connect to the US interstate grid. It will bind every RTO and ISO, making it the only federal mechanism capable of overriding the patchwork of local moratoriums. FERC commits to act by end of June 2026.Source: FERC / Mayer Brown / data-centres update 2

Who opened FERC Docket RM26-4-000 and why?

Energy Secretary Chris Wright opened RM26-4-000 in October 2025 under Section 403 of the DOE Organisation Act, directing FERC to create rules for fast-tracking large electricity loads above 20 MW. It is a direct response to hyperscaler demand for rapid grid access.Source: DOE / FERC / data-centres update 2

What are the three contested questions in the FERC large-load interconnection rulemaking?

Per Mayer Brown's analysis: (1) whether hyperscalers can bypass standard interconnection studies; (2) how behind-the-meter solutions are treated for cost allocation; and (3) who pays for transmission upgrades triggered by large loads. The answers will determine whether RM26-4-000 accelerates or burdens new data-centre projects.Source: Mayer Brown / data-centres update 2

Does FERC RM26-4-000 apply to Texas data centres?

No. ERCOT operates outside FERC's jurisdiction. Data centres in West Texas using behind-the-meter arrangements at brownfield crypto-mining sites are entirely outside the RM26-4-000 scope, which is why that region has emerged as the fastest large-scale AI compute alternative to FERC-jurisdictional grids.Source: FERC jurisdictional scope / data-centres context

When will FERC rule on the large-load data centre grid order?

FERC committed on 16 April 2026 to act on RM26-4-000 by end of June 2026. The proceeding was opened in October 2025; FERC moved about two months past the DOE's preferred 30 April Deadline.Source: FERC / data-centres update 2

Source Material

FERC to act on large load interconnection docket in June 2026

How the World Sees Them

Europe

European grid operators are watching RM26-4-000 as a potential model for reforming their own large-load connection queues, though the EU's regulatory structure differs substantially.

United States

Hyperscalers and utilities see RM26-4-000 as the most consequential energy policy decision for data-centre infrastructure in a decade; the cost-allocation outcome could add or remove hundreds of millions per project.