FERC RM26-4 Is About to Change Data Center Interconnection. Here Is What Developers Should Do Before It Does.

FERC's June 2026 large-load interconnection rulemaking will set the first national standards for connecting data centers above 20 MW to the grid -- and the window to act before those standards land is closing.

On April 16, 2026, the Federal Energy Regulatory Commission issued a formal order committing to act in Docket No. RM26-4-000 before the end of June 2026. That date is not a target or an aspiration. FERC set it in writing, and the Commission stated its action will be "quick, efficient and legally durable."

For data center developers, this is the most consequential federal regulatory action on load interconnection in the Commission's history. The rulemaking will establish the first standardized national framework for connecting loads above 20 megawatts directly to the interstate transmission system. Every developer with a project above that threshold needs to understand what is coming and what to do about it before the order lands.

What RM26-4 Is Expected to Contain

The Advance Notice of Proposed Rulemaking laid out 14 guiding principles. Based on the comment record, the SPP HILL Tariff precedent from January 2026, and the PJM co-location order already in place, the June action will likely standardize four core elements.

A 20 MW trigger. Any load connecting directly to FERC-jurisdictional interstate transmission above 20 MW will be subject to the new framework. Some commenters argued the threshold is too low and captures commercial and industrial loads the rule was not designed for. Whether FERC adjusts this or holds at 20 MW will be confirmed in the order, but developers should assume any hyperscale or large-scale colocation project is in scope.

100% caused-cost assignment. The most commercially significant provision. Under this framework, large-load interconnection customers would be assigned 100% of the network upgrades required to accommodate their connection -- mirroring how generators are treated under the pro forma LGIA/LGIP regime. Potential crediting mechanisms exist, but the baseline assumption shifts transmission upgrade costs squarely onto the load customer's pro forma. For large sites in congested markets, this can represent tens to hundreds of millions of dollars in previously unmodeled exposure.

Expedited study pathways for curtailable loads. The ANOPR raised the possibility of completing interconnection studies in as few as 60 days for loads willing to accept contractual curtailability. This is a question, not a finalized timeline, but it introduces a new tradeoff: accept curtailability provisions to get faster queue processing, or hold out for firm capacity on standard timelines. For data centers running AI inference workloads, curtailability is a serious operational constraint. For lower-priority compute workloads, it may be an acceptable exchange.

Hybrid facility treatment. Co-located generation and load will be studied together based on net injections and withdrawals. A 500 MW data center with a 600 MW generating facility, for example, could potentially request no grid withdrawal rights and 100 MW of injection rights. This opens new structuring options for developers pairing on-site generation with data center load, but requires deliberate interconnection strategy at the project design stage.

What Is Not Certain

Important caveats. The RM26-4 ANOPR is not a final rule. It is an advance notice, which means FERC could advance an ANOPR, a Notice of Proposed Rulemaking, an order, or some combination. The June action will be the framework, but compliance timelines and enforcement mechanisms will likely follow in subsequent proceedings.

Grandfathering or phase-in provisions for existing queue positions are expected. Projects already in queue under current regional interconnection rules will likely not face retroactive application of the new cost assignment framework. New queue applications filed after the June order is effective face more exposure.

ERCOT is not subject to FERC jurisdiction over transmission interconnection, so Texas developers operating entirely within the ERCOT footprint should monitor state-level proceedings separately. ERCOT's own large-load policies are evolving independently.

Five Actions Before the Order Lands

1. Map your queue exposure. For every active project above 20 MW in FERC-jurisdictional territory, document the current interconnection study status, any executed large-load interconnection agreements, and which network upgrades have been scoped. Establish a baseline before the rule changes the cost allocation framework.

2. Model 100% caused-cost scenarios. For projects where network upgrades have been identified but not assigned, run pro forma sensitivities assuming full cost responsibility. If the development economics break at full caused-cost assignment, that is a site selection and capital structure question, not just a regulatory question.

3. Evaluate curtailability options. For data center projects where the compute workload has flexibility, assess whether a curtailability provision in exchange for expedited study timelines improves overall project schedule. This is a workload and tenant coordination question as much as a regulatory one.

4. Assess hybrid generation structuring. If a project involves on-site generation -- gas turbines, solar, battery storage -- model the interconnection as a hybrid facility and quantify the net injection/withdrawal position. Projects that look like net injectors may have more favorable treatment under the framework.

5. Engage interconnection counsel. The June 2026 order will generate compliance filings from every transmission provider in FERC-jurisdictional territory. Utilities will have their own interpretation of what is required. Having interconnection counsel tracking the order as it drops and translating it into project-specific implications is not optional for active large-load development programs.

AI can monitor the FERC docket, utility compliance filings, and interconnection queue databases to keep a real-time picture of how the order is being implemented across regions. That monitoring layer is where automation adds clear value. The strategic response to the order -- how to structure interconnection agreements, whether to accept curtailability, how to manage network upgrade cost exposure -- requires engineering and legal judgment that AI supports but does not replace.

The window between now and June 30 is short. Procurement decisions made in that window will be executed while FERC is finalizing rules. Treat RM26-4 outcomes as a forward sensitivity in current underwriting, and build action items around the five steps above before the order changes what the baseline looks like.