It’s that time of the year when seniors must choose a healthcare plan. It’s Medicare open-enrollment time, but beware of making Medicare mistakes.

Medicare Advantage plans will be filling the airwaves with their enticing advertisements to join their plans. Medicare Advantage plans are not the federal government; they are private insurance plans for seniors who are eligible for Medicare. Their advertising makes them appear to be government plans, but they are entirely managed by private companies. This may be a good thing, if they provide you with more coverage for less money, but beware of the limitations of these plans.

According to the Center for Medicare Advocacy, as of March 2023, 65,748,297 people were enrolled in Medicare, an increase of almost 100,000 since the last report of September, 2022. Of those, 33,948,778 were enrolled in Original Medicare and 31,799,519 were enrolled in Medicare Advantage or other health plans. That’s nearly half of all seniors enrolled in Medicare.

Why the popularity of Medicare Advantage plans? They generally give you more coverage for the money. They usually provide benefits greater than Original Medicare, such as dental, vision, and fitness coverage. They usually cost less, too. So why doesn’t every senior sign up for Medicare Advantage?

An article in The Wall Street Journal, by Anna Wilde Mathews tells us why. Lothaire Bluteau, 66 years old, an actor who lives in West Hollywood, Calif., last year enrolled in one of the private plans known as Medicare Advantage. After he was diagnosed with prostate cancer last May, he discovered the specialists he wanted to see weren’t in his UnitedHealthcare HMO’s limited network. He faced delays getting tests and treatment.

He got a bigger shock when he tried to get access to more doctors by switching to traditional Medicare, run by the federal government. Bluteau worried about the steep out-of-pocket costs, so he tried to get a fill-in policy known as a Medigap plan that would cover many of those expenses. Yet health insurers said no because of his cancer diagnosis. He didn’t realize he could be rejected. “I didn’t inform myself enough,” Bluteau said. “I was so stupid.”

Bluteau’s struggle to get a Medigap plan shows one of the risks seniors may miss when they are selecting coverage. Medicare beneficiaries generally don’t know that they have a right to get Medigap policies only at certain times, and if they don’t jump then, they might not be able to purchase them later. Medicare’s open-enrollment period kicked off Sunday and goes until Dec. 7. During that time, beneficiaries can pick new plans for next year. The options include traditional Medicare from the government, or the wide array of Medicare Advantage plans, which are private-insurance products that wrap in the same benefits.

Pitfalls to Avoid

If you are a senior going through open enrollment this fall, here are five pitfalls to avoid:

Medigap Trap

Patients with health issues may want to move to original Medicare, but they can’t buy Medigap or Medicare Supplement policies. Medigap, or Medicare supplement insurance, doesn’t have the same rules as most health insurance. For other types of coverage, insurers can’t reject you or charge you more based on your medical conditions. With Medigap, such guarantees are available only at certain times. Medigap is vital for many people who enroll in traditional Medicare. The original government program can leave beneficiaries with big out-of-pocket bills for their care, and there is no cap on how high that tab can go. Medigap policies help cover those costs.

The best time to get a Medigap plan is when you first join Medicare when you turn 65. Then you have a six-month window to buy your policy. After that you must find a protected window, such as if you opt out of Medicare Advantage during a limited initial “trial period.” State rules vary so check with your own state department of insurance.

Wrong Doctors

Another common trap that can ensnare people who sign up for Medicare Advantage plans: a lean menu of doctors and hospitals. The plans—particularly health maintenance organizations, or HMOs—can have limited networks that sometimes mean beneficiaries can’t go to the doctors or hospitals they want. When Bluteau chose his HMO plan on the advice of an insurance agent, he said, he didn’t realize it lacked doctors he would want to see. He was ultimately able to switch to a different UnitedHealthcare Medicare Advantage plan, a preferred provider organization or PPO, that included them.

You can find directories of in-network doctors on the insurers’ websites, but be careful. “They can be wildly inaccurate,” said Julie Carter, senior federal policy associate at the Medicare Rights Center, a nonprofit. “It’s a mess, and we don’t really have a great solution other than doing a lot of legwork.” Don’t just trust—be sure to verify. You should call the doctor offices and hospitals that matter to you, and consider looking up other providers you might need unexpectedly, such as nursing homes. You should call the insurer, and be specific about what plan you are researching and which doctors and hospitals you want.

(Author’s Note: There are three more pitfalls to avoid. We’ll cover those in my next blog.)