DUKE ENERGY FLORIDA, LLC

The litigation matter of NTE Carolinas II, LLC Litigation included in Part 1, Item 1 of this Quarterly Report on Form 10-Q, within Note 5, "Commitments and Contingencies" of the Condensed Consolidated Financial Statements, is incorporated herein by reference.

In addition, the Duke Energy Registrants are, from time to time, parties to various lawsuits and regulatory proceedings in the ordinary course of their business. For information regarding legal proceedings, including regulatory and environmental matters, see Note 4, "Regulatory Matters," and Note 5, "Commitments and Contingencies," to the Condensed Consolidated Financial Statements. For additional information, see Item 3, "Legal Proceedings," in Duke Energy's Annual Report on Form 10-K for the year ended December 31, 2024.

For open litigation, unless otherwise noted, Duke Energy cannot predict the outcome or ultimate resolution of these matters.

MTBE Litigation

In December 2017, the state of Maryland filed suit in Baltimore City Circuit Court against Duke Energy Merchants and other defendants alleging contamination of state waters by MTBE leaking from gasoline storage tanks and is seeking an unspecified amount of monetary damages. MTBE is a gasoline additive intended to increase the oxygen levels in gasoline and make it burn cleaner. The case was removed from Baltimore City Circuit Court to federal District Court. Initial motions to dismiss filed by the defendants were denied by the court in September 2019, and the matter is now in discovery. In December 2020, the plaintiff and defendants selected 50 focus sites, none of which have any ties to Duke Energy Merchants. Discovery will be specific to those sites. Duke Energy Merchants has reached an agreement in principle with the state of Maryland to resolve the litigation. The settlement agreement is being finalized and the amount is not material.

The Town of Carrboro Litigation

On December 4, 2024, the town of Carrboro, North Carolina, filed a lawsuit against Duke Energy in the North Carolina Superior Court, Orange County, alleging that Duke Energy and its predecessor companies knew since the late 1960s that fossil fuel emissions could cause global climate changes and engaged in a campaign to conceal the dangers of fossil fuel emissions from the public, regulators, legislators, and others, resulting in a delayed transition away from fossil fuel emissions and worsening climate change. The lawsuit also alleges that Duke Energy misled the public regarding Duke Energy’s support for, and actions toward, transitioning its fossil fuel portfolio to renewable energy. The damages alleged range from road and stormwater system impacts to increased electricity costs and recurring invasions and interferences from extreme weather events. The lawsuit asserts state law claims for public nuisance, private nuisance, trespass, negligence, and gross negligence, and is seeking an unspecified amount of monetary damages. The case has been transferred to the North Carolina Business Court. Duke Energy filed a motion to dismiss the litigation based on lack of subject matter jurisdiction on March 17, 2025, and filed a motion to dismiss based on failure to state a claim on which relief can be granted on May 9, 2025. Oral argument regarding Duke Energy's motions to dismiss was held on September 25, 2025. As requested by the court, supplemental briefing addressing various aspects of causation, including traceability and proximate cause, was filed on October 25, 2025.