Northern Light Health said Friday that it is ending stalled contract negotiations with Anthem Blue Cross Blue Shield, further increasing the potential that its hospitals and health care providers may soon no longer be in-network for thousands of Mainers.

If the two sides do not reach an agreement, Anthem health insurance plans would be considered out-of-network for Northern Light Health hospitals, which include Eastern Maine Medical Center in Bangor and Mercy Hospital in Portland, as well as a large network of primary and specialty care providers. Out-of-network services typically cost more for patients.

Northern Light said in a written statement Friday afternoon that it would consider continuing talks with Anthem “in the event that Anthem comes back with a reasonable offer.” Anthem said in its own statement that it was disappointed by Northern Light’s announcement but remains committed to striking an agreement.

The two companies’ contract expires Sept. 30, though Anthem has said previously that the current deal includes an extension period of at least 90 days to allow further negotiations.

The impasse could affect thousands of patients statewide. Brewer-based Northern Light is Maine’s second-largest health care network, while Anthem is Maine’s largest private insurance carrier.

In its Friday statement, Northern Light said it had sent a letter to Anthem leadership detailing what it described as “issues and concerns” that have come up during the monthslong negotiations, including withholding interim payments for services and a “cumbersome” prior authorization operation.

“It is unfortunate that Anthem has decided not to focus its efforts on engaging in productive discussions to negotiate an agreeable deal that would benefit our patients by ensuring continued payment for the services Northern Light Health provides,” James Rohrbaugh, Northern Light’s executive vice president and chief financial officer, said in a written statement Friday. “To continue delivering this high level of service, we rely on fair and sustainable partnerships with insurers like Anthem. We need Anthem to come alongside us through a contract that reflects our region’s unique health care needs and economic environment.”

If a new agreement is not reached, Northern Light said physicians and some services will be out-of-network starting Oct. 1, while hospital-based services will be out-of-network on Dec. 31. The entire Northern Light system will be out of network with all Anthem Medicare Advantage Plans come Jan. 1, 2026, the health care system added.

In a written statement Friday evening, Anthem said it will continue to work to reach an agreement with Northern Light.

“We at Anthem are disappointed to learn that Northern Light Health is indicating they will discontinue negotiations – with several weeks and months to go before their contracts with Anthem are supposed to terminate,” the statement reads in part. “We remain committed to working with Northern Light to reach a new contract in the weeks ahead. It’s the right thing to do for our members who are Northern Light patients. So, we intend to keep the lines of communication open.”

Anthem said Northern Light’s current demands would cause an increase of more than $200 million in health care costs for Anthem’s customers over the life of the proposed three-year agreement, which the insurance company said is “not in the best interest of our members.” Anthem also says it is concerned by Northern Light’s request to drop compensation related to quality of care.

Anthem has also previously disputed Northern Light’s statements regarding the timing of the end of in-network care if a new agreement is not struck.

“Anthem Blue Cross and Blue Shield and Northern Light Health are currently in discussions to continue member access to affordable care at Northern Light’s doctor’s offices and hospitals beyond December 30, 2025,” Anthem said in a written statement in June. “Unfortunately, Northern Light’s statements referencing September 30 are misleading. Our current contract runs through that date, however it includes a minimum 90-day extension to allow both parties continued negotiation time to avoid member care disruption.”

Editor’s note: This story has been updated to include a statement from Anthem.