FERC issues Federal Power Act Section 206 show-cause orders to all six RTOs/ISOs on large-load interconnection — RM26-4-000 rulemaking itself remains un-acted-on

Opening

FERC did not close Docket RM26-4-000 with a NOPR or final rule in June 2026 as trade press had projected following its April 16, 2026 “Intent to Act” order. Instead, on approximately June 18-19, 2026, FERC used a different statutory lever — Federal Power Act Section 206 “show cause” authority — to order all six jurisdictional RTOs/ISOs (PJM, MISO, SPP, ISO-NE, NYISO, CAISO) to individually justify or reform their existing large-load interconnection tariff provisions on a reported 60-day compliance clock. As of the most recent Federal Register data available (FERC’s own August 14, 2026 Unified Regulatory Agenda), RM26-4-000’s official timetable still shows no NPRM or Final Rule action — only the October-November 2025 ANOPR comment-period entries, with the docket’s own listed “Next Action” as “Undetermined,” projected November 2026.

What Happened / Key Facts

The mechanism shift: Rather than issuing a single generally-applicable rule under the RM26-4-000 rulemaking docket, FERC used Section 206 of the Federal Power Act — its “just and reasonable rate” enforcement authority — to open individual show-cause proceedings against each RTO/ISO’s existing tariff. This is a materially different regulatory tool than a rulemaking: it forces each grid operator to defend or amend its own rules rather than imposing one uniform federal standard. Named in three independent secondary sources: McGuireWoods (“FERC Issues Section 206 Show Cause Orders Directing All Six RTOs/ISOs to Justify or Reform Large Load [Interconnection],” June 22, 2026), White & Case (“FERC orders grid operators to promptly revise or justify interconnection rules for data centers,” June 25, 2026), and RTO Insider (“FERC Directs RTOs to Fix Large Load Interconnections as Answer to DOE ANOPR,” June 18, 2026; corroborated by Utility Dive, “6 takeaways from FERC’s data center interconnection decision,” June 22, 2026).

The compliance clock and RTO responses (through August 2026): Trade coverage describes a roughly 60-day compliance window. Subsequent RTO Insider headlines document individual grid-operator responses:

• FirstEnergy (PJM member) proposed directly assigning transmission-upgrade costs to data-center customers (June 8, 2026 — filed ahead of/around the order)
• SPP reported confidence in meeting the compliance deadline (June 30, 2026)
• MISO began designing a dedicated interconnection-queue process specifically for large loads (July 20, 2026); separately, MISO postponed (“stalled”) a zero-injection generation proposal for large loads after stakeholder pushback (dated in reporting to mid-June 2026)
• CAISO filed a “Large Load Proposal to Address Show-cause Order” (August 13, 2026)
• “Every ISO/RTO Asks FERC for an Extra 3 Months on Large Loads” (RTO Insider, August 4, 2026) — indicating the original 60-day compliance deadline was not met on schedule industry-wide, and a coordinated extension request was pending as of early August 2026

RM26-4-000 status per FERC’s own regulatory agenda: FERC’s August 14, 2026 Unified Regulatory Agenda entry for RIN 1902-AG47 (“Interconnection of Large Loads to the Interstate Transmission System,” Docket No. RM26-4-000) lists a timetable ending at “Comment Period End 11/21/25” and “Reply Comment Period End 12/05/25,” followed by “Next Action Undetermined 11/00/26” — i.e., FERC’s own official accounting, as of mid-August 2026, does not commit to any specific further rulemaking action and does not reflect a June 2026 NOPR or final rule having issued. This textually confirms that the June Section 206 show-cause orders were not filed as, and did not substitute for, action within the RM26-4-000 docket itself.

Why This Event Matters

FERC chose enforcement-by-proceeding over rulemaking-by-rule. The Wright directive of October 23, 2025 compelled FERC to act on a generally-applicable rulemaking (RM26-4-000) by April 30, 2026. FERC missed that deadline (documented in 2026-04-16–ferc-rm26-4-000-misses-april-30-deadline-intent-to-act-june-2026), then in June 2026 answered the underlying policy problem — inconsistent, slow large-load interconnection processes — through a different, narrower mechanism: individual Section 206 proceedings against each grid operator’s tariff. This is not a “paper action”: RTOs are visibly filing real compliance responses (cost-allocation proposals, new queue designs) through August 2026. But it is also not the rule Wright’s directive specifically ordered. The distinction matters because Section 206 proceedings produce RTO-specific outcomes (PJM’s rules may end up different from MISO’s or CAISO’s), rather than the single national standard the ANOPR contemplated — a fragmentation outcome, not the “quick, efficient, and legally durable” uniform standard FERC’s own April 2026 order language promised.

The compliance clock has already slipped. The August 4, 2026 report of all ISOs/RTOs jointly requesting a three-month extension indicates the 60-day compliance window (running from roughly mid/late June to mid/late August 2026) was not met industry-wide. Combined with RM26-4-000’s own “Undetermined” next-action status, the datacenter-interconnection-reform lever of the July 23, 2025 EO package remains operationally unresolved fifteen-plus months after Wright’s directive and twenty-two-plus months after the EO itself — not reversed, not abandoned, but still in a procedurally live, unresolved state.

Access limitations (disclosed)

This entry rests on convergent secondary-source headlines and article summaries, not on the primary FERC order text or its exact docket citation for the Section 206 proceedings. ferc.gov returned Cloudflare 403 responses to both evidence-search’s browser escalation (blocked at the tool’s public-records allow-list, since ferc.gov is not on it) and to direct WebFetch, consistent with this KB’s standing note that ferc.gov has been blocked this session. Several law-firm alert pages (White & Case, McGuireWoods) and most individual RTO Insider article URLs returned 403 or 404 when fetched directly — likely paywall/CMS-gating rather than a Cloudflare challenge specifically. The finding is corroborated across four independent outlets (two law firms, two trade publications) reporting the same June 18-19, 2026 date and the same Section 206/show-cause characterization, which is a reasonable evidentiary basis for the fact of the order’s issuance and general content — but exact docket numbers for the individual RTO show-cause proceedings, the precise compliance-deadline date, and any dissenting-commissioner statements were not independently verified against the primary order. Anyone tightening this citation should retry ferc.gov via a non-blocked browser session or pull the order from a legal database (Westlaw/Lexis FERC service).

Research Gaps

• Exact docket number(s) for the individual Section 206 show-cause proceedings against each RTO/ISO
• Exact issuance date and compliance-deadline date of the June order(s) — sources converge on June 18-19, 2026 for issuance but the precise 60-day deadline math was not independently confirmed
• Whether FERC granted the RTOs’ pending three-month extension request (as of August 4, 2026, reported as pending)
• Whether any FERC commissioner dissented from the Section 206 show-cause orders
• Whether RM26-4-000 (the rulemaking itself) will ever produce a generally-applicable rule, or whether FERC has effectively substituted individual Section 206 tariff reform as its permanent resolution mechanism
• Content of PJM’s, MISO’s, and CAISO’s actual compliance filings (cost allocation terms, threshold definitions) once accessible via a non-blocked route

Related Entries

• 2026-04-16–ferc-rm26-4-000-misses-april-30-deadline-intent-to-act-june-2026
• 2025-10-23–doe-directs-ferc-anopr-large-load-interconnection
• 2025-07-23–eo-accelerating-federal-permitting-data-center-infrastructure
• datacenter-permitting-deregulation-2025
• wright-chris
• epic-inv6-energy-systems-convergent-demand-shock

Conductor note, 2026-08-28 — status set to reported, and what IS primary-verified

Downgraded confirmed → reported to match the entry’s own sourcing disclosure. The body states plainly that it “rests on convergent secondary-source headlines and article summaries, not on the primary FERC order text” — an entry cannot be confirmed on that basis. The disclosure itself is exemplary and is why the downgrade is a one-word fix rather than a rewrite.

Context for the strictness: a canon sourcing audit the same day found two of twelve high-importance confirmed entries asserting claims their sources do not contain. confirmed has to mean something.

What IS primary-verified, checked by the conductor against the Federal Register directly: FERC’s own Unified Regulatory Agenda (2026-08-14, 91 FR / doc 2026-16616) lists “Interconnection of Large Loads to the Interstate Transmission System,” RIN 1902-AG47, at ANPRM stage with “Next Action Undetermined, 11/00/26.” A fedreg search returns no NPRM and no final rule for this docket. So the entry’s core structural claim — FERC did not proceed by rulemaking — is confirmed from a primary source, independent of the law-firm alerts.

What remains secondary-sourced: the Section 206 show-cause orders themselves (four independent outlets — McGuireWoods, White & Case, RTO Insider, Utility Dive — agreeing on the June 18-19 date and the Section 206 characterization), the exact docket numbers, the precise compliance deadline, and any dissents. ferc.gov 403s (Cloudflare; not on evidence-search’s allow-list), so no claim here rests on a successfully-read ferc.gov page.

To restore confirmed: pull the primary order text from a non-blocked browser session or a legal database and cite the docket numbers directly.