Americans on Medicare Advantage plans may soon get a breakup letter in the mail: Your insurer is canceling your plan.

Humana and other Advantage insurers are sending letters this fall to plan members about 2027 coverage. As insurers look to cut costs, some are discontinuing their Advantage plans.

Humana has said that about 600,000 of its members, or nearly 9% of its enrollment, will be affected by plan exits for 2027. Smaller regional carriers are scaling back, too: In New Mexico, for example, Presbyterian Healthcare Services will be discontinuing most of its Advantage plans.

"Those notices should be hitting people's mailboxes basically now," says Louise Norris, health policy analyst at medicareresources.org. More than 35 million people are on Advantage plans, and cancellations are expected to affect up to 10% of them. That would represent a big uptick from the average 1% exit rate that prevailed from 2018 to 2024, according to a study published in JAMA earlier this year.

"If you're the person getting that notice, it matters a lot," Norris says.

If your plan is being discontinued, you'll have the opportunity to select a new one during the open enrollment period that begins on Oct. 15. Those who do nothing will be automatically enrolled in traditional Medicare starting on Jan. 1; you'll have to add a Part D drug plan and Medigap policy on your own. Window shopping for 2027 plans on Medicare.gov begins on Oct. 1.

Meanwhile, it's a good opportunity for everyone-not just those whose plans are being canceled-to assess your needs for the coming year and line up enrollment help if you'd like support.

The annual fall open enrollment offers Medicare recipients an opportunity to select new coverage for the coming year. You can move between Medicare Advantage run by private insurers and traditional Medicare run by the federal government. It's also an opportunity to switch from one Advantage plan to another, and for those on traditional Medicare, to choose a new Part D drug plan.

Medigap, the optional plans that supplement traditional Medicare, isn't part of open enrollment. Medigap is primarily run by the states, and you can apply at any time. However, outside of certain periods and a handful of states with different rules, insurers aren't required to sell you a policy-you can be charged more or denied coverage altogether based on pre-existing conditions.

One exception: Advantage enrollees who have been forced out of their plan. They have the option to return to traditional Medicare and buy a Medigap plan without medical underwriting. For those who chafed at Medicare Advantage coverage restrictions, which can include limited doctor choices and prior authorization and referral requirements, the ability to buy a guaranteed Medigap policy could be welcome.

Medicare choices can be overwhelming, and a knowledgeable broker can help. Be wary of marketers who target older adults on Facebook, says Alex Doonanco, CEO of careCycle, an artificial-intelligence customer service platform for Medicare agencies. They may sell your data and encourage plan hopping.

It's often best if you can sit down with a local broker, Doonanco says. Medicare Agents Hub is one place to find an independent broker, who should be available to answer your questions throughout the year.

Look for an agent who sells plans from multiple carriers, rather than one who represents one company. Multi-carrier agents are generally paid the same commission regardless of which plan you choose, so they can focus on finding the best fit. One way to ensure that is to ask, "Do you have full inventory in my area?" Doonanco says.

You can find free, unbiased help at your local State Health Insurance Assistance Program, or SHIP. Appointments tend to fill up quickly around open enrollment, so don't wait until the last minute. For round-the-clock help, 64Plus offers an unbiased, AI-powered education and decision platform for a monthly fee of $7.99.