This week, I answer questions from readers who are concerned about Medicare and insurance for long-term care.

Q: Can getting a genetic test interfere with being able to buy long-term-care insurance in the future? If you do get a plan, can the insurer drop you after you find out the results of a genetic test?

In general, long-term-care insurers can indeed use genetic test results when they decide whether to offer you coverage. The federal Genetic Information Nondiscrimination Act prohibits health insurers from asking for or using your genetic information to make decisions about whether to sell you health insurance or how much to charge. But those rules don’t apply to long-term-care, life or disability insurance.

When you apply for long-term-care insurance, the insurer may review your medical records and ask you questions about your health history and that of your family. It’s all part of the underwriting process to determine whether to offer you a policy and how much to charge.

If the insurer asks you whether you’ve undergone genetic testing, you generally have to disclose it, even if the testing was performed through a direct-to-consumer site like 23andMe, said Catherine Theroux, a spokeswoman for LIMRA, an insurance industry trade group.

Consumers applying for a long-term care policy should release any medically relevant information, she said.

Some states provide extra consumer protections related to genetic testing and long-term-care insurance, said Sonia Mateu Suter, a law professor at George Washington University who specializes in genetics and the law. But most follow federal law.

If you get genetic testing after you have a policy, the results can’t affect your coverage.

“Once the policy has been underwritten and issued, the insurer doesn’t revoke the policy if new medical information comes to light,” Theroux said.

Q: Can I switch Medigap insurance companies midway through the year? I found a less expensive policy.

It depends. Under federal law, when people turn 65 and first enroll in Medicare Part B they have a six-month window to sign up for a Medigap plan. Medigap plans pick up some of beneficiaries’ out-of-pocket costs for services under Medicare Part A, which covers hospitalization, and Medicare Part B, which covers outpatient services. During that six-month period, insurers have to accept people even if they have health problems.

If you’re still in that six-month period now and you want to switch plans, go right ahead.

But if you’re past the six-month window, under federal law insurers are required to sell you a plan only in certain circumstances, such as if you lose your retiree coverage or Medicare Advantage plan. If you don’t meet the criteria, insurers can decline to cover you or charge you more for preexisting medical conditions.

Many states have provided more robust protections, however. Three states — Connecticut, Massachusetts and New York — have year-round open enrollment and require insurers to offer coverage. And Maine requires a one-month “guaranteed issue” open-enrollment period every year.

Some states guarantee current policyholders a chance to switch Medigap plans at certain points during the year. Other states have additional qualifying events that allow people to switch Medigap plans, according to data from the Kaiser Family Foundation. (Kaiser Health News is an editorially independent program of the foundation.)

“The first thing the person should do is check with her state insurance department to find out her rights related to buying a Medigap plan,” said Brandy Bauer, associate director at the Center for Benefits Access at the National Council on Aging. If someone decides to go ahead and switch, it is wise to sign up for a new plan before terminating your current policy, she said.

Q: I did not enroll in Medicare Part B when I turned 65 because I already have a regular plan that covers everything. I was told that the insurer would keep paying as usual, but now the company says it will pay only part and that I have to buy Medicare Part B. I didn’t want to pay for two policies. Is there anything I can do to avoid that?

From your description, it’s hard to know exactly what’s going on, but we can make educated guesses. Typically, when people turn 65, it makes sense to sign up for Medicare unless they or their spouse are working and getting health insurance from an employer. For others, at age 65, Medicare typically becomes their primary insurer and any other coverage they have becomes secondary, filling in gaps in Medicare coverage.

That’s how it generally works with retiree coverage, said Tricia Neuman, director of the Program on Medicare Policy at the Kaiser Family Foundation.

If you have an individual policy that you bought on the health insurance exchange and decide to hang on to it instead of signing up for Medicare, your premiums and other costs could be higher than they would be on Medicare, depending on your income.

But if you’re not receiving employee coverage and you don’t enroll in Medicare Part B, you could be subject to a permanent premium penalty of 10 percent for every 12 months that you could have signed up for Part B but didn’t. You could also owe a premium penalty for not signing up for a Part D prescription drug plan. (Most people don’t owe any premium for Medicare Part A, so there’s no penalty for late sign-up.)

“Without knowing more, it sounds like she should drop the [current] plan and sign up for Part B and D,” Neuman said. “But we need more information to know for sure.”

Your best move now may be to call 800-Medicare or visit your local state health insurance assistance program (SHIP) to help sort out your coverage issues.

Please visit kffhealthnews.org/columnists to send comments or ideas for future topics for the Insuring Your Health column.