If you are a Generator Owner, Transmission Operator, or compliance manager with inverter-based resources in your fleet, the next nine months represent the most consequential compliance window the industry has seen since FERC Order 901 launched the current wave of IBR rulemaking. Two hard deadlines are bearing down fast. A new EMT modeling mandate went live on April 1, 2026. And NERC's April 2026 supplemental compliance matrix has reshuffled which standards are enforceable right now versus which ones are still winding through the standards development process.
This post cuts through the noise. We will tell you exactly what is enforceable, when, and what your organization needs to do before the calendar runs out.
Why 2026 Is the Year IBR Compliance Gets Real
For years, inverter-based resource compliance existed in a kind of regulatory gray zone. Legacy standards were written for synchronous generators. IBR-specific rules were perpetually "in development." Enforcement actions were rare. That era is over.
NERC has spent the better part of four years investigating IBR performance failures — from the 2016 Blue Cut Fire event through a string of more recent disturbances — and the regulatory response is now arriving in force. Three new performance standards (PRC-028, PRC-029, and PRC-030) are moving toward enforcement. MOD-026-2, which for the first time explicitly mandates electromagnetic transient (EMT) modeling for power-electronic facilities, became effective April 1, 2026. And FERC has approved a second package of IBR standards covering model validation and data sharing across every major RTO in the country.
The question is no longer whether your solar, wind, or battery storage fleet needs to comply. The question is whether your organization will be ready before the deadlines hit — or whether you will be scrambling to explain gaps to your Regional Entity.
The PRC-028/029/030 Trilogy: What Each Standard Requires
PRC-029-1: Ride-Through Performance for Frequency and Voltage
Of the three new performance standards, PRC-029-1 is the one getting the most attention — and for good reason. It establishes minimum ride-through criteria for frequency and voltage excursions, requiring solar, wind, and battery storage resources to remain connected and performing during grid disturbances rather than tripping offline and compounding the event.
Critically, PRC-029-1 adopts the IEEE 2800 performance curves as its technical foundation. These curves are materially more stringent than the legacy PRC-024 voltage ride-through envelope that most Generator Owners have been designing to for the past decade. If your interconnection agreement was executed against PRC-024 requirements, your current plant settings may not satisfy PRC-029-1 — and a gap assessment is not optional at this point, it is urgent.
The standard applies to BES-connected IBRs (generally those at or above 100 kV, or generating facilities with a gross nameplate rating of 20 MVA or greater at the point of interconnection) under the October 1, 2026 compliance deadline. Non-BES IBRs — smaller facilities that aggregate to BES significance — face a subsequent deadline of January 1, 2027.
PRC-028 and PRC-030: Model Verification and Protection System Coordination
PRC-028 addresses model verification requirements for IBRs, ensuring that the dynamic models submitted to RTOs and used in planning studies actually reflect how the physical plant behaves. This standard directly addresses one of NERC's most persistent findings: that IBR models submitted by Generator Owners routinely underperform their real-world counterparts in disturbance simulations, leading planners to underestimate cascading risk.
PRC-030 targets protection system coordination, requiring that IBR protection settings be reviewed and documented to confirm they do not conflict with the ride-through requirements established under PRC-029-1. In plain terms: you cannot set your inverter protection to trip at a voltage or frequency threshold that falls inside the mandatory ride-through envelope. Sounds obvious — but NERC's post-event analyses have found exactly this mismatch at a significant number of operating facilities.
Together, PRC-028, PRC-029-1, and PRC-030 form an interlocking compliance framework. Weakness in any one leg undermines the others.
MOD-026-2: The EMT Modeling Mandate Is Already in Effect
While the PRC deadlines are the most visible countdown on the compliance calendar, Generator Owners should not overlook a standard that quietly crossed its effective date on April 1, 2026: MOD-026-2.
What Changed from MOD-026-1
The original MOD-026-1 focused on model verification for synchronous generators. MOD-026-2 expands the scope explicitly to cover IBRs, HVDC facilities, and FACTS devices — any facility where power electronics, rather than rotating mass, dominate the dynamic response. More importantly, it introduces a formal requirement for electromagnetic transient (EMT) modeling for power-electronic-based facilities.
EMT modeling is a significant step up in technical complexity from the positive-sequence phasor models that most Generator Owners have historically submitted. EMT models capture sub-cycle dynamics — the behavior of inverter controls, phase-locked loops, and protection logic at microsecond timescales — that positive-sequence tools simply cannot represent. NERC's disturbance investigations have repeatedly shown that positive-sequence models fail to predict IBR behavior during severe voltage events, which is precisely why the EMT requirement was added.
The Four-Year Runway — and Why You Should Not Wait
MOD-026-2 provides a full compliance runway through April 1, 2030 for Generator Owners to complete all model verification, validation, and submission activities. Four years sounds generous. It is not.
EMT model development requires detailed vendor data (often protected as proprietary), specialized simulation software (PSCAD, EMTP, or equivalent), and engineering expertise that is in short supply across the industry. The consultants and software vendors who can support this work are already booking out. Generator Owners who wait until 2028 or 2029 to begin will find themselves competing for scarce resources against hundreds of other facilities facing the same deadline — and facing Regional Entity scrutiny for evidence-of-progress gaps in the interim.
MOD-026-2 also introduced tightened frequency deviation thresholds for model acceptance: the Eastern Interconnection threshold dropped from 0.05 Hz to 0.04 Hz, and the ERCOT threshold dropped from 0.10 Hz to 0.08 Hz. Models that previously passed validation may need to be resubmitted.
RTO-Specific Implications: PJM, MISO, ERCOT, and Beyond
The new IBR standards do not exist in a vacuum — they layer on top of RTO-specific interconnection requirements, market rules, and planning processes that vary significantly across regions. Here is what Generator Owners in three major footprints need to know.
PJM
PJM has been among the most aggressive RTOs in pushing for IBR model quality improvements, and the approval of MOD-032, MOD-033, and TOP-003 as part of FERC's second IBR standards package (approved February 20, 2026) directly affects PJM-interconnected resources. MOD-032 and MOD-033 govern steady-state and dynamic model data requirements, while TOP-003 addresses transmission operations data sharing. PJM Generator Owners should expect increased scrutiny of model submissions and faster rejection of models that do not meet the new validation thresholds.
FERC has also directed PJM specifically to reform its rules governing generation interconnection and transmission service for generators co-located with large loads — a rulemaking with direct IBR implications as data center co-location projects proliferate across the PJM footprint. If you have a solar-plus-storage project co-located with a hyperscale load, the interconnection rules you planned to are likely changing.
MISO
MISO's footprint spans a large share of the nation's utility-scale wind capacity, and PRC-029-1's ride-through requirements will require settings reviews at a significant number of operating wind facilities that were commissioned under older interconnection agreements. MISO has historically required adherence to its own LVRT/HVRT specifications in generator interconnection agreements — but those specifications predate the IEEE 2800 curves that PRC-029-1 now mandates. The gap between what MISO required at the time of interconnection and what PRC-029-1 requires today is real and needs to be quantified.
MISO Generator Owners should also note that MOD-026-2 and the associated EMT modeling requirements apply equally in MISO's footprint. MISO planning staff have been signaling for over a year that positive-sequence-only model submissions for IBR-heavy areas will face increasing scrutiny.
ERCOT
ERCOT operates as an electrical island with its own frequency response characteristics, and the tightened MOD-026-2 frequency deviation threshold (0.10 Hz → 0.08 Hz) is directly relevant to ERCOT-interconnected IBRs. ERCOT has been at the center of multiple high-profile IBR disturbance events, and NERC's investigations of those events are part of the documented performance history that drove the PRC-028/029/030 rulemaking in the first place.
ERCOT Generator Owners face a somewhat different regulatory pathway since ERCOT is not subject to FERC jurisdiction in the same way as the Eastern Interconnection — but NERC reliability standards apply, and the October 1, 2026 BES deadline is not ERCOT-optional.
NERC's April 2026 Compliance Matrix: What Is Enforceable Right Now
NERC's April 2026 supplemental compliance dates document provides important clarity on the Category 2 IBR applicability picture. Not every standard that will eventually apply to Category 2 IBRs (smaller inverter-based resources that fall below traditional BES thresholds) is enforceable today.
The document confirms that MOD-026 and MOD-027 remain "In Development" under Project 2020-06 for Category 2 IBR applicability. PRC-023 through PRC-027 and TOP-001 all require further modification before becoming applicable to Category 2 resources. Each of these standards will go through individual commenting and ballot periods before becoming enforceable.
What this means practically: if you are a Category 2 IBR owner, you have a defined set of currently enforceable standards to focus on — and a longer list of standards that are coming but not yet final. The responsible approach is to begin gap assessment work against the currently enforceable set immediately, while monitoring the standards development pipeline for the Category 2 expansions that are coming.
For Category 1 BES-connected IBRs, the picture is more urgent. The October 1, 2026 deadline for PRC-029-1 compliance is firm, and the eight standards initially identified as applicable to Category 1 IBRs are enforceable now.
Your 90-Day Action Plan
Given the October 1, 2026 deadline for BES-connected resources and the January 1, 2027 deadline for non-BES resources, here is what your organization should be executing on right now:
- Conduct a PRC-029-1 ride-through gap assessment against the IEEE 2800 voltage and frequency curves for every IBR in your fleet. Compare current inverter settings against the new ride-through envelope and identify any settings that fall inside the mandatory stay-connected zone.
- Audit PRC-030 protection coordination to confirm that no protection functions are set to trip within the PRC-029-1 ride-through envelope. This requires coordination between your relay engineers and your inverter OEM.
- Initiate MOD-026-2 EMT model development for any facility at or above the applicable MVA threshold. Do not wait for the 2030 deadline — begin vendor data collection and model scoping now.
- Review your RTO model submissions against the new MOD-032 and MOD-033 data requirements, particularly if you are in PJM, MISO, or SPP where model rejection rates have been increasing.
- Map your Category 2 assets against NERC's April 2026 compliance matrix to understand which standards are currently enforceable versus in development for your smaller facilities.
Talk to an Expert
GridStrong helps generator owners and operators navigate IBR compliance requirements. Contact us to discuss your compliance strategy.
Our team specializes in PRC-028/029/030 gap assessments, MOD-026-2 EMT model development, and Category 2 IBR compliance mapping across all major RTO footprints. With the October 1, 2026 BES deadline fewer than six months away, the time to act is now — not after the crunch begins.
