The Minnesota Hospital Association said the state's largest not-for-profit health insurer, Blue Cross Blue Shield of Minnesota, is probably breaking the law by imposing a slate of new policies designed to deny or delay access to routine colonoscopies and hundreds of other services in hospitals.

The hospital trade group is asking state officials to investigate the practices of the state Blue Cross plan and stop the insurer from imposing new policies that the hospitals said make it more difficult and expensive for Minnesotans to access routine and lifesaving health care services. The hospital group said state law doesn't appear to allow Blue Cross to discriminate against in-network providers as it intends to, and that the health plan's policies may violate laws on unfair and deceptive trade practices, among other legal issues.

But the insurer said health care costs continue to rise to unprecedented levels, and hospitals must work with payers and plan sponsors to improve the sustainability of health care costs. In some cases, hospitals have been given the chance to lower their prices in order to gain coverage of a particular service, and some have done so. A spokesman said the insurer is confident that the plan changes are legal.

"It's important to understand that health care premiums reflect the costs and claims they cover, and more than 90% of every dollar we collect in premiums goes directly to pay for care for our members," Blue Cross said in a statement Monday. "We believe it's important to take action that can help keep care and coverage affordable.

Minnesota Hospital Association CEO Lawrence Massa sent a 27-page letter to the state attorney general and the state commissioners of health and commerce Monday asking their offices to investigate Blue Cross and Blue Shield of Minnesota, and block any policies that break the law, harm plan subscribers or "negate" Minnesota Blue Cross' legal obligations to Minnesota hospitals.

"Blue Cross ... wants to save itself money," said Matthew Anderson, senior vice president of policy at the MHA. "You still need to meet provider network-sufficiency standards under the law. You still need to deal with your subscribers up front, and fairly and honestly. You still need to honor your contract with providers, where you have contracted to pay them a given amount for a given service. ... And you still have to pay providers when they deliver a service that was medically necessary to a person that you insure. You can't just say you're not going to pay them."

Attorney General Keith Ellison said his office plans to investigate the hospitals' concerns.

"It will take a while to dig into all the concerns MHA raised, but we take them seriously and will look into them seriously," Ellison said in an e-mail from a spokesman Monday.

The association, representing 141 Minnesota hospitals, is protesting two types of coverage restrictions.

First, the hospitals said the insurer is imposing new requirements that patients obtain prior authorization for services, making it more difficult and time-consuming for patients to obtain coverage for more than 250 different services, even though the requests are ultimately approved.

The hospital association also said the insurer is declaring some services won't be covered even when provided to an eligible patient at an in-network hospital. For example, endoscopy services including routine colonoscopies to check for colon cancer wouldn't be covered at an in-network community hospital if there's a cheaper ambulatory surgery center within 25 miles, the association said.

The state Health Department recently spent $500,000 on a public campaign urging residents to get screened for colorectal cancer, the hospital group noted. "Limiting BCBS subscribers' access, making it more difficult for them to get these medically necessary treatments and diagnostic services, and increasing patients' delays and travel distances to have these procedures run counter to the state's underlying interest in public health and the general welfare of our residents," the hospital association letter said.

Blue Cross said its policy for services like endoscopies is identical to rules recently implemented by the federal government for Medicare beneficiaries.

"When certain procedures cost less at a specialty outpatient clinic than it does in a hospital setting — and the quality of care is as good or better — it is our job to make sure our members are being guided to that clinic," the insurer said in a statement. "Hospitals also have the option of meeting outpatient clinic pricing to allow their patients to have the procedure within their hospital. Many hospitals have elected this option."

The insurer said the 2018 Minnesota Health Care Cost & Utilization Report recently found that imaging services in outpatient hospital settings were 45% more expensive than the same services at a specialty clinic.

Regarding its new policies on prior authorization of services, Blue Cross said it's part of a contractual requirement first established in 2015, and the insurer started holding informational meetings with providers about it more than a year ago.

"Similar prior authorization practices are implemented by other payers in Minnesota and across the nation to ensure patients receive care that is medically necessary and evidence-based," the insurer's statement said.