A change in federal law is forcing hundreds of thousands of elderly Minnesotans to replace their health plans that supplement Medicare coverage.

Medicare is the national health insurance program for people age 65 and older and some disabled people. Many buy supplemental insurance to help pay the portion of health costs Medicare does not cover.

About 350,000 Minnesotans are losing their Cost plans. And at an advanced age, they now have to sort through options that would be complex and confusing for anyone.

"Beneficiaries that previously never did anything during open enrollment now have to make a change for the first time in many, many years, if ever," said Minnesota Board on Aging Health Policy analyst Kelli Jo Greiner.

The board's Senior LinkAge line is having trouble keeping up with demand for help, she said.

"It's not only confusing, it's very frustrating."

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Greiner said the best way to get through is to call during specially extended hours — Monday through Thursday between 4:30 p.m. and 6 p.m. She said a lot of people calling the Senior LinkAge line are angry about being forced into different coverage.

"They love their Cost plan. They don't want to make a change. They want to stay with it, but I think they're starting to understand that this really is a critical time for them to make a change so they have coverage Jan. 1," Greiner said.

Cost plans pay for medical bills at any Medicare-approved provider — there's no specified provider network. Medicare is trying to cut back on Cost plans to save money. Cost plans are going away in areas where there are at least two Medicare Advantage plans to choose from. But Advantage plans specify a provider network.

The Minnesota Council of Health Plans said its members are also busy helping customers make the switch, said Jim Schowalter, president of the trade organization that represents Minnesota's major health insurers.

"The phones are literally ringing off the hooks because it's a big deal for seniors in Minnesota," he said.

State officials say insurers are automatically enrolling about half of the Minnesotans losing their Cost plans in Advantage plans. The rest — some 175,000 seniors — are on their own to find a replacement.

"That is the group we're most concerned with," said Greiner.

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Medicare enrollees who don't find a Cost plan replacement by the end of the year will only have the stripped down original Medicare coverage starting Jan. 1. There won't be a monthly supplemental premium to pay, but they'll be responsible for any expenses Medicare doesn't cover after that.

"Come January, they're going to go to the doctor [or] end up in the hospital and have this huge bill," Greiner said.

People caught in that unfortunate situation will have until the end of February to enroll in an Advantage plan. But they'd still be on the hook for any expenses Medicare doesn't pay before their new coverage kicks in.

There is another option beyond an Advantage plan called a Medigap plan. It's generally more expensive than an Advantage plan because its provider network is wide open. That's what Kristine Lund, 53, of Savage selected. She's disabled, on Medicare and thoroughly annoyed.

"What I found now is still not as good as what I had with the Cost plan," she said.

Lund said her new plan increases her monthly premium by about 40 percent. Lund's advice is to shop carefully.

"And ask exactly what they cover because a lot of them have skimped on the coverage now," she said.

Help finding a plan is available at Medicare.gov and also regionally through the Senior LinkAge line in Minnesota and the various health insurance companies.

Schowalter said Cost plan holders who need to switch and haven't done so yet should not put it off any longer.

"Now's the time to get some background. Make sure you have a plan and have some conversations about what kind of Medicare you want next year," he said.