It's crunch time for about 45,000 people treated by doctors with Fairview Health Services who also have a Medicare health plan from Blue Cross and Blue Shield of Minnesota.

For weeks, Blue Cross and Fairview have been notifying patients that a contract dispute means people with Blue Cross coverage might not have access to Fairview at the lower in-network rates starting in January.

Such contract disputes often get resolved at the 11th hour — which would mean late December in this case — but open enrollment for Medicare beneficiaries ends Wednesday.

Seniors must decide this week whether to stick with Blue Cross and risk losing access to Fairview physicians at the lowest cost, or jump to a Medicare health plan from a different insurer.

"The turmoil is awful," said Iric Nathanson, 76, of Minneapolis, who is in the process of switching health plans. "The most important thing for us was to stay in the Fairview system."

Blue Cross said there would be varying degrees of impact to people with different types of Medicare coverage. The insurer sells Medicare health plans as well as Medicare supplemental policies.

"In any case, there would be some level of in-network coverage that would process through Original Medicare," the insurer said in a statement. "However, treatment for any care that's not included in the Original Medicare benefit set would be subject to out-of-network benefits."

In a statement, Fairview said it understands the contract dispute is creating "stress and uncertainty" for Medicare patients. But the health system said it continues to talk with Blue Cross, with the goal of reaching agreement so care and coverage aren't interrupted.

"We are hopeful that an agreement can be reached, and will update patients as more information is available," Fairview said via e-mail.

Eagan-based Blue Cross is one of the state's largest health insurers. Minneapolis-based Fairview is one of the state's largest operators of hospitals and clinics, running the University of Minnesota Medical Center in Minneapolis and Fairview Southdale Hospital in Edina.

In early November, Blue Cross started sending letters to about 170,000 subscribers in commercial health plans notifying them of the conflict. In mid-November, the insurer followed up with mailings to 45,000 people in Medicare plans.

Blue Cross also is notifying people covered through state public programs (39,000) and federal government employees (10,000). Overall, more than 250,000 people with a recent history of seeing Fairview doctors could lose access to the health system at in-network rates.

"Letters were sent to those members who had a Fairview primary care or specialist visit in the last 12 months," Blue Cross said in a statement.

Fairview has said it is negotiating for "the necessary reimbursement level to fund our mission and support exceptional patient care." In a statement to the Star Tribune last month, Fairview said the health system has "a strong focus on delivering exceptional care and service while working to reduce the total cost of care."

Blue Cross posted a statement on its website in late November that didn't mention Fairview specifically but explained why the insurer makes network changes. "If we determine that a clinic or hospital is asking for a pay increase that is well beyond market standards," Blue Cross said, "then we have an obligation to challenge those assumptions.

Richard Lett, an insurance agent with LeClair Group in Woodbury, said brokers are helping people switch plans if they are in the midst of a course of treatment at a Fairview facility or have a strong connection with Fairview providers.

In other cases, it might make sense for people just to stay put, Lett said, especially since contract disputes usually settle, often at the brink of contract expirations.

"The fact that negotiation overlies the open enrollment, and negotiations could go beyond Dec. 7 — that's what causes all the problem, because no one's got a crystal ball," Lett said.

A contract dispute between Minnetonka-based Medica and Minneapolis-based Children's Hospitals and Clinics of Minnesota went public in November 2014 and was settled within a few weeks. There was no patient impact. That was also true of a dispute between Blue Cross and Regions Hospital in St. Paul that settled in December 2013.

Last year, however, Medica and the mental health care provider PrairieCare could not reach an agreement on financial terms before a contract expired.

Nathanson, the Minneapolis resident who is switching plans, said he wished letters from Fairview and Blue Cross had more clearly called out the open enrollment issue. He said he and his wife have had good care from Fairview for many years and good results with Blue Cross, so they haven't had to shop around for coverage.

"It took me an hour poking around on the computer to even realize that if I didn't act in the next few days, I would be out of luck," he said. "It would have been a massive problem for us to change all of this [with Fairview] in order to stay with Blue Cross."

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck