Liz Weston

Dear Liz: You recently wrote about Medicare Advantage plans, which often cover things like dental care, hearing and vision that traditional Medicare does not. You mentioned that the plans have networks of providers, but people should know that those networks don’t always include the experts they may need if they develop serious health issues. The plans themselves can have copays that make it expensive to get sick. If people want to switch to traditional Medicare and get a supplemental Medigap policy, they may face medical underwriting that could increase their costs.

Answer: Medicare Advantage plans are sold by private insurers as an all-in-one alternative to traditional Medicare. The plans are certainly popular — the percentage of Medicare beneficiaries who sign up for Medicare Advantage has been steadily increasing over the years, in part because these private plans seem to cover more. But the plans can vary widely in the breadth of their networks and how they share costs with beneficiaries.

Once you’ve signed up for Medicare Advantage, switching to traditional Medicare can be problematic, as you noted. Insurers aren’t required to cover you the way they are when you first enroll. Some may decline to offer you a Medigap policy or may charge you more, based on your health.