Sanford Health says it is dropping out of the network for Medicare Advantage plans from Humana, alleging the Kentucky-based health insurer continually delays patient care and denies coverage for services.

The move, which is being announced in letters to nearly 10,000 patients in Minnesota, takes effect next year and comes about one month after Bloomington-based HealthPartners said it would leave Minnetonka-based UnitedHealthcare's network in 2025, citing concerns about payment delays and denials.

Humana is one of the nation's largest operators of Medicare Advantage health plans, a form of coverage where seniors elect to receive their government health care benefits through a private managed care company.

Sanford Health, which is based in South Dakota, has significant operations in western and northern Minnesota including hospitals in Bemidji, Thief River Falls and Worthington.

"While a difficult decision, ending our partnership with Humana Medicare Advantage is the right thing to do for our patients," the health system said in an Aug. 23 letter reviewed by the Minnesota Star Tribune. "We have attempted to work with Humana for several years, but unfortunately, we have continued to experience delays in patient care, barriers to scheduling and denials of coverage causing financial burden and undue stress to our patients."

Humana called the health system's announcement surprising because Sanford Health has "not voiced any of these concerns during our conversations this year," the insurer said in a statement.

"We remain open to working with them on a fair and equitable agreement that keeps health care coverage affordable for our members and avoids the significant disruption that this decision will cause," the insurer said. "Humana strives to provide access to high quality health care for our health plan members while minimizing out-of-pocket costs."

With Medicare Advantage plans, seniors often face higher out-of-pocket costs when visiting out-of-network providers. So, seniors in Humana plans who want to minimize those expenses will face a choice between switching to a new Medicare Advantage plan that includes Sanford Health in its network or sticking with their current health plan and finding new health care providers.

Alternately, seniors can revert to the original Medicare program, although they might not be able to purchase a Medicare Supplement policy to cover out-of-pocket costs that can be significant.

In the network dispute this summer between HealthPartners and UnitedHealthcare, the health system has said it will not let the insurance company's Medicare Advantage customers use out-of-network benefits next year at HealthPartners hospitals and clinics. Sanford Health, however, said Humana subscribers will be able to get care at the health system on an out-of-network basis.

"We provide care to all patients, regardless of insurance," the health system said in a statement to the Minnesota Star Tribune.

Asked if negotiations for a 2025 network agreement with Humana might still move forward despite the letters recently sent to patients, Sanford Health said via email: "No. Starting Jan. 1, 2025, Sanford Health will end participation with Humana Medicare Advantage."

Sanford will remain in-network through the end of the year, so Humana subscribers don't need to take any action now. Seniors can consider options during the annual Medicare Advantage open enrollment period from Oct. 15 through Dec. 7.

And health system officials say the termination does not impact any facilities operated by Good Samaritan Society, the division for skilled nursing care at Sanford Health. These facilities will continue to be in-network for patients with Humana coverage, the health system said.

Overall, Sanford Health said it sent letters to 19,094 patients who had Humana coverage at a visit in the past two years. Sanford says Humana has been losing membership, so the actual number of people affected by the network change could be 4,000 to 5,000 fewer.

For Humana, it's the fourth instance in recent years of a significant network change with large health care providers in Minnesota.

In June 2023, HealthPartners announced it would drop out of Humana's Medicare Advantage network for 2024, a move that affected about 13,000 seniors. In October 2020, Humana said M Health Fairview and CentraCare were opting out of the health plan's network for the following year, a shift that affected more than 10,000 Minnesotans.

At UnitedHealthcare, the network change for next year affects about 30,000 Medicare beneficiaries who use clinics and hospitals run by HealthPartners.