Federal Energy Regulatory
Court keeps 9.98% MISO rate in place, limiting refunds
The D.C. Circuit said Louisiana regulators could not force a new look at the benchmark rate, and it also narrowed transmission owners' path to another round of refunds.
The 9.98% return used in the MISO transmission case stays in place after the D.C. Circuit rejected Louisiana's bid to reopen the fight. The panel also said transmission owners did not clear the standing hurdle on part of the challenge, which trims the path to more refunds.
- The 9.98% MISO return stays in place for now.
- Louisiana regulators could not reopen the rate fight.
- Transmission owners failed to clear a standing hurdle on part of the case.
- The ruling narrows the path to more refunds on disputed charges.
- Circuit left the 9.98% return used in the Midcontinent Independent System Operator, or MISO, transmission dispute in place on June 5, 2026, shutting down Louisiana regulators’ latest bid to reopen the fight
The D.C. Circuit left the 9.98% return used in the Midcontinent Independent System Operator, or MISO, transmission dispute in place on June 5, 2026, shutting down Louisiana regulators’ latest bid to reopen the fight. For electric customers on the regional grid, that means the benchmark rate still feeds disputed charges, and the refund question does not get a fresh reset.
The benchmark that keeps driving the bills
The court said its earlier MISO Transmission Owners decision controls here: the Federal Energy Regulatory Commission, or FERC, must apply the return in effect when it makes a decision, including in related proceedings. On that view, Louisiana’s challenge to FERC’s use of the 9.98% return was foreclosed by the law-of-the-case doctrine, rather than reopened for another look at the merits.
That matters because the 9.98% figure is not just a number in a legal fight. It is the benchmark feeding into transmission charges on the MISO grid, so keeping it in place affects what customers may pay or get back on disputed bills.
A narrower path to refunds
The transmission owners also ran into a separate barrier. The court said they lacked Article III standing to challenge FERC’s consideration of a successive complaint because they did not show redressability for one claimed injury or imminence for another.
That standing ruling does not erase the underlying rate fight, but it does shrink the remaining route to another round of refunds tied to the disputed return.