On September 12, 2025, the PJM/MISO Interconnection held their Joint and Common Market (JCM) meeting, a recurring forum aimed at improving coordination across two of the nation’s largest regional transmission organizations. With growing renewable penetration, shifting load patterns, and expanding transmission needs, the discussions underscored the urgency of harmonizing rules and approaches to support cross-regional reliability and cost efficiency.
Key Discussion Items from PJM/MISO JCM Meeting
1. Transmission Cost Allocation Across Borders
One of the most heavily debated topics was how to manage cost allocation for transmission projects that provide benefits to both regions.
- Stakeholders raised concerns that current frameworks may undervalue regional benefits when projects straddle the seam, leading to cost-shifting disputes.
- PJM representatives stressed that any revisions must preserve fairness for ratepayers in both regions.
- MISO stakeholders highlighted the importance of ensuring cost allocation methodologies reflect real system benefits, particularly given the rise of long-haul renewables and regional congestion relief projects.
Both RTOs acknowledged the complexity and committed to refining their benefit metrics and cost-sharing methodologies in future workshops.
2. Queue Reform and Cross-Border Interconnection Issues
The JCM also examined how differing interconnection processes create friction for projects that sit along the MISO/PJM seam.
- Developers noted the challenges of submitting projects into two queues with different timelines, study assumptions, and upgrade requirements.
- Several participants pushed for harmonized study processes, or at minimum, improved transparency between RTOs when projects affect both grids.
- PJM emphasized recent reforms to its interconnection queue under FERC Order 2023 compliance, while MISO outlined its ongoing efforts with ERAS (Enhanced Resource Assessment Studies).
PJM/MISO Stakeholders urged both RTOs to consider joint approaches for projects at the seam to reduce redundancy and uncertainty.
3. Resource Adequacy and Planning Reserve Sharing
The conversation also touched on the potential for closer coordination in resource adequacy planning.
- MISO staff outlined the ongoing challenges of maintaining reserves amid rapid retirements of thermal assets and seasonal variability in renewable output.
- PJM representatives noted similar concerns but stressed that differences in planning criteria and reserve margin methodologies make joint planning difficult.
- Several stakeholders asked whether increased reserve sharing could lower overall costs and enhance reliability across both systems, especially during extreme weather events.
The RTOs agreed to continue evaluating the potential benefits of reserve coordination but noted regulatory and tariff complexities remain significant hurdles.
4. Market-to-Market Coordination Enhancements
Another focus was improvements to the Market-to-Market (M2M) coordination process, which governs how the two RTOs manage congestion relief on flowgates affecting both systems.
- Market participants expressed frustration with limited transparency on M2M settlements and congestion management decisions.
- MISO staff acknowledged the concerns and proposed enhanced reporting to provide better visibility into cross-border congestion drivers.
- PJM echoed the need for refinements, especially as transmission congestion increasingly intersects with renewable development zones.
5. Long-Term Transmission Planning Alignment
Finally, the PJM/MISO JCM examined long-term planning priorities, particularly the potential to align MISO’s Long Range Transmission Planning (LRTP) efforts with PJM’s Regional Transmission Expansion Plan (RTEP).
- Stakeholders argued that better alignment would unlock significant efficiencies, especially for projects delivering renewable power from MISO’s resource-rich areas into PJM’s load centers.
- Concerns were raised about regulatory approval processes and differences in how each RTO values public policy drivers.
- Both RTOs expressed willingness to coordinate further, noting that FERC’s pending transmission planning reforms may provide additional guidance and requirements.
Key Takeaways for Developers and Market Participants
The September 12 PJM/MISO JCM meeting highlighted both the progress and the challenges of coordinating planning and market rules across MISO and PJM. Developers with projects near the seam must carefully track evolving interconnection and cost allocation rules, as these can directly influence project feasibility and economics.
While no immediate rule changes were finalized, the meeting signaled continued momentum toward greater transparency, harmonization, and joint analysis. Stakeholders should expect follow-up sessions as both RTOs refine cost allocation methodologies, evaluate queue reforms, and explore opportunities for improved reserve sharing and congestion management.
At ZEG, we understand that navigating the complexities of MISO, PJM, and their joint coordination efforts requires more than technical expertise—it demands foresight, strategy, and the right tools. Our engineering advisory services, combined with REST®, grid siting and analytics tool, equip developers with defensible insights into grid conditions, interconnection risks, and transmission planning dynamics across multiple ISOs.
If your projects operate in MISO, PJM, or along the critical seam between the two, reach out to us here. We help turn the uncertainty of evolving market rules into actionable strategies for successful project development.
View PJM/MISO JCM Meeting Materials here.
