FERC opens Section 206 proceeding against ISO New England

Cresthaven Analytics Intelligence Brief

Headline

FERC opens Section 206 proceeding against ISO New England and sixteen transmission owners over potentially unjust rates

Executive Summary

FERC instituted a Section 206 proceeding on June 24, 2026 against ISO New England and sixteen named New England transmission owners, establishing a refund effective date. The proceeding initiates a formal review of whether existing rates, terms, or conditions on file are unjust, unreasonable, or unduly discriminatory.

Bottom Line

The proceeding places ISO New England's tariff and the rates of sixteen transmission owners under formal Commission review, with refund liability accruing from June 24, 2026. Each named transmission owner carries respondent status and must engage in the proceeding to defend its filed rates. Any Commission finding of unjust or unreasonable rates carries retroactive refund exposure to the established effective date, creating a contingent financial liability that sits on the books of every named entity from the date of institution.

Key Regulatory Signals

Refund Effective Date Established: FERC's institution of the proceeding sets a refund effective date as of June 24, 2026. ISO New England and all sixteen named transmission owners are now exposed to potential refund obligations running from that date if rates are ultimately found unjust or unreasonable.
Sixteen Transmission Owners Named as Respondents: The proceeding names Central Maine Power, Connecticut Light and Power, Fitchburg Gas and Electric, Green Mountain Power, Maine Electric Power, Narragansett Electric, New England Power, New Hampshire Transmission, NSTAR Electric, Public Service Company of New Hampshire, United Illuminating, Unitil Energy Systems, Vermont Electric Cooperative, Vermont Electric Power Company, Vermont Transco, and Versant Power. Each named entity carries direct respondent status and associated compliance exposure.
ISO New England Tariff Under Scrutiny: The proceeding subjects ISO New England's filed tariff to formal Commission review. Any rates, terms, or conditions found deficient must be revised to meet the just and reasonable standard, with changes potentially applied retroactively to the refund effective date.
Peer Transmission Owners Outside New England Should Assess Exposure: A Section 206 proceeding of this scope, covering an entire RTO and its full transmission-owner roster, signals active Commission scrutiny of regional transmission rate structures. Other RTOs and transmission owners with analogous tariff provisions face a relevant precedent if FERC's findings produce a broadly applicable rate-design ruling.

Regulatory Delta

- FERC has used Section 206 proceedings against RTOs previously, including actions against PJM and MISO, but naming an entire RTO alongside its full transmission-owner roster in a single docket is a broad-scope action for the New England region.

- The June 24, 2026 refund effective date is the structurally significant new element. It creates immediate financial exposure for all named respondents before any merits determination.

- The current Commission has signaled heightened attention to transmission cost allocation and rate design in 2025 and 2026, consistent with its Order 1920 transmission planning framework issued in May 2024.

Materiality Classification

HIGH — FERC has formally instituted a Section 206 proceeding with a refund effective date against ISO New England and sixteen transmission owners, creating immediate contingent refund liability for all named respondents and establishing a precedent relevant to transmission rate structures across other RTOs.

Intelligence Outlook

Monitor FERC docket activity for this proceeding for responsive filings from ISO New England and the named transmission owners, any Commission order setting a hearing or settlement judge, and any proposed rate revisions filed to address the identified deficiencies.