The annual open enrollment period for people selecting a Medicare health plan ends Friday, but that doesn't mean the shopping season is over for more than 300,000 Minnesotans who are losing their Medicare Cost coverage next year.

Beginning Saturday, people losing Cost plans will be eligible for a special enrollment period where they have until month's end to buy replacement coverage that takes effect Jan. 1, and enrollment options that stretch into 2019.

Last month, the Minnesota Board on Aging said the Friday deadline applied to Cost plan enrollees who want to buy a stand-alone Part D plan for drug coverage, but it turns out the special enrollment period applies to Part D plans, too.

"We got some clarification on that," said Kelli Jo Greiner, health policy analyst with the Minnesota Board on Aging. "The urgency is not what it is for the other folks, because [people losing Cost plans] do have a special enrollment period. But the sooner people can make a decision, the better it will be for them."

For most of the 1 million Minnesotans on Medicare, Friday is the deadline for enrolling in a stand-alone Part D plan, which supplements coverage in the original Medicare program, or a Medicare Advantage (MA) plan, where people obtain Medicare benefits through a private health insurer.

The board on aging expects Friday will be a busy day at the state's Senior LinkAge Line, which provides free help for people considering their options.

"It's that crunch time where people that haven't really given it a thought realize: 'It's Dec. 7 and I better do something,' " Greiner said.

Medicare open enrollment happens every year, and it's not an issue for those who rely solely on original Medicare. That's also true for those who buy a "Medigap" policy that supplements the core government program, since people can apply to purchase supplementary coverage at any time.

But the 2018 shopping season has been unusually hectic due to the change with Cost plans, which are being eliminated by federal law across 66 counties in Minnesota next year.

Those losing the coverage have been encouraged to use the sign-up period to consider original Medicare versus the newer MA plans. State officials say people leaving Cost plans should avoid surprise bills next year by enrolling in an MA plan that includes drug coverage or by supplementing original Medicare with Medigap and Part D policies.

Across the country, about two-thirds of beneficiaries are covered by original Medicare, but a growing number have been picking Medicare Advantage.

Medicare Advantage plans often come with lower premiums than the combined premium for a Medigap and Part D plan. Some MA plans don't charge a monthly premium. MA plans also offer extras such as vision, dental and hearing benefits.

Original Medicare, on the other hand, provides wider access to doctors and hospitals and gives people a choice of Part D coverage from a variety of companies. While Medicare itself only covers 80 percent of costs in many cases, people who use the government program in tandem with Medigap and Part D coverage can see lower copayments for doctor and hospital care than with MA plans.

Among those losing Cost plans, about 142,000 people are being automatically enrolled in new MA plans from their current insurer, although they are free to make a different choice. Some of those being automatically enrolled in an MA plan are finding their doctor is not in the new health plan's network, Greiner said, and there are cases where the new MA plan's drug coverage brings much higher copayment requirements.

People losing Cost plans have a one-time right to buy a Medigap plan without answering questions about their health history, which could block enrollment at a later date. This "guaranteed issue" right extends until March 4.

"We have never had so many requests for information on Medigap policies as we have had this year," Greiner said.

Even so, Minneapolis-based UCare, which is the state's largest Medicare Advantage insurer, says it's had a very busy open enrollment period, with consumers drawn by the combined medical and prescription coverage that's part of most MA plans.

"On Friday, our team will be onsite and available for phone consultations and enrollments until at least 8 p.m., longer if warranted by volume," said Wendy Wicks, a UCare spokeswoman, via e-mail. "Online enrollment will be available until midnight as well fax service for applications."

Blue Cross and Blue Shield of Minnesota, HealthPartners and Medica all sell Cost plans, and those companies for 2019 also are selling Medigap plans and Medicare Advantage plans, depending on the county. Kentucky-based Humana sells Medigap plans as well as Medicare Advantage plans in most Minnesota counties.

In 2019, Minnesotans in certain counties can buy Medicare Advantage plans sold by Minnetonka-based UnitedHealthcare as well as a joint venture between Connecticut-based Aetna and the Allina Health System, which is based in Minneapolis.

Beyond contacting the state's Senior LinkAge Line (1-800-333-2433) or health insurance companies, consumers can get help from insurance agents, the website or by phoning Medicare (1-800-633-4227).

Christopher Snowbeck • 612-673-4744 Twitter: @chrissnowbeck