By Laura Christensen, Sr NERC Reliability Specialist
The North American Electric Reliability Corporation (NERC) has completed a major expansion of its Generator Owner (GO) and Generator Operator (GOP) registration requirements for certain inverter-based resources (IBRs). Beginning May 15, 2026, NERC registered qualifying Category 2 IBR facilities and made an initial group of Reliability Standards applicable to those entities. NERC reported that 449 GO/GOP entities representing 531 Category 2 IBR facilities had been identified for registration. These non-BES inverter-based resources are categorized by inverter-based resource generation facilities that have an aggregate nameplate capacity of 20 MVA or more and are interconnected at 60 kV or higher.
For Category 2 facilities, the initial compliance obligations are centered on eight Reliability Standards: BAL-001-TRE-2, IRO-010-5, MOD-032-1, PRC-012-2, PRC-017-1, TOP-003-6.1, VAR-001-5 (in WECC only), and VAR-002-4.1. These standards became applicable to qualifying Category 2 GOs and GOPs upon their registration effective date, subject to the applicable jurisdictional approval and implementation requirements. Additionally, these standards are now applicable to Category 2 GOs and GOPs: MOD-026-2, PRC-024-4, PRC-028-1, PRC-029-1, PRC-030-1.
The significance of the Category 2 change is that registration does not automatically make every NERC Reliability Standard applicable. NERC specifically identified standards that currently apply without modification, while other standards require revisions before Category 2 resources can be brought into their applicability. In particular, standards that are written specifically for BES Facilities generally do not become enforceable against Category 2 facilities until an approved standards project expands their applicability.
Several protection and planning standards remain identified for future Category 2 applicability. NERC’s Category 2 compliance-date documentation identifies PRC-019, PRC-023, PRC-025, PRC-026, PRC-027, TOP-001, and TPL-007 as standards requiring modification before Category 2 IBRs can become subject to those requirements. This is particularly important for facilities that are already performing protection coordination, relay loadability, voltage/frequency protection, or other studies under existing requirements. A Category 2 facility should not assume that a standard listed as requiring modification is presently enforceable solely because the facility is now registered.
At the same time, NERC advanced broader IBR-related standards work. For example, PRC-029 addresses frequency and voltage ride-through requirements for IBRs, while PRC-030 addresses unexpected IBR event mitigation. These standards are part of NERC’s continuing response to the reliability risks associated with increasing IBR penetration. Both became enforceable on October 1, 2026 under their respective implementation plans.
Additionally, for those facilities who may not meet the January 1, 2027 deadline for Category 2, PRC-029 implementation deadlines due to OEM’s and some vendors, NERC has released guidelines on how to seek enforcement discretion. Registered entities must notify their regional entity before the compliance deadline with explanations on how they have attempted to comply, why they will not meet the deadline, and when their expected date of compliance will be. The enforcement discretion ends 24 months from the applicable design compliance date.
NERC is also continuing work under FERC Order No. 901 to improve IBR data, modeling, operational studies, and performance requirements. The 2025-03 Operational Studies project has advanced FAC-011-5 and TOP-003-9, with the standards moving toward Board adoption and regulatory filing. The project specifically addresses IBR performance and behavior in operational assessments and real-time monitoring. Separately, Project 2021-01 continues work associated with model validation and revisions involving MOD-025 and PRC-019.
For Category 2 sites, the practical takeaway is that 2026 represents the beginning—not the end—of the compliance transition. GO-2 and GOP-2 entities should maintain a current applicability matrix, understand the eight standards applicable to their registration on May 15th, standards that have become effective since the date of registration, and monitor pending standards projects that could expand requirements into protection, modeling, operations, and planning. NERC’s standards development process remains active, and applicability can change as revisions are approved by the NERC Board and subsequently approved by the applicable regulatory authorities.
