12 FAQs About Medicare: Your Medicare Questions Answered

It's time to get your Medicare questions answered if you turn 65 in the next few years. There’s a lot at stake, but you're not alone. The years 2024 through 2027 will be record-breaking for retirement. Over 10,000 Americans are expected to celebrate their 65th birthday every day. So take a moment to familiarize yourself with Medicare basics.

You have to pick supplemental insurance to fill Medicare’s coverage gaps, and you might have to switch to less-expensive versions of some medications. But don't put these decisions off. If you don’t sign up by the deadline or make other mistakes, you could end up with lifetime penalties, denied claims or big bills you shouldn’t have to pay.

Sign-up Medicare questions: 

1. Do I need to sign up for Medicare, or will I be enrolled automatically? If you signed up for Social Security before age 65 (eligibility for full benefits currently begins at age 66 if you were born from 1943 to 1954 and 67 thereafter), you will automatically be enrolled in Medicare parts A and B and receive your card three months before your 65th birthday. Part A covers hospitalization and is generally premium-free; Part B covers outpatient care, such as doctors’ visits, x-rays and tests, and costs $185.00 monthly for people who enroll in 2025 (or more for high earners).

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Everyone else needs to take steps to enroll — or face a lifetime late-enrollment penalty (unless you’re still working and have employer coverage; see below). Go to socialsecurity.gov to sign up anytime from three months before until three months after you turn 65 (your “initial enrollment period”), even if you are waiting to file for Social Security benefits.

2. I’m still working. Do I need to sign up? That depends on the size of your company. If you or your spouse (if you’re covered by your spouse’s insurance) is still working for a firm with 20 or more employees, the employer’s insurance is your primary coverage, and Medicare is secondary and can fill any gaps in coverage. You aren’t required to sign up for Medicare at 65, and you won’t have a late-enrollment penalty as long as you sign up within eight months of leaving your job and losing work-based coverage (or losing coverage under your spouse’s insurance).

If you work for a large employer and are happy with its coverage, you may decide to delay signing up for Part B. (Many people still sign up for Medicare Part A at 65.) But the rules are different if you work for a company with fewer than 20 employees. In that case, Medicare generally becomes your primary coverage at age 65, and you need to sign up for Part A and Part B while you’re still working. Some small employers negotiate with insurers to keep employee coverage primary for workers after age 65, but this is unusual; get it in writing from your boss before you delay signing up.

Also note that you can’t delay signing up for Part A if you’re already receiving Social Security benefits and were automatically enrolled in Medicare — even if you’re still working.

3. I have a health savings account (HSA) at work. Can I still contribute to my health savings account after I turn 65? Yes, you can continue to contribute to your HSA if you haven’t enrolled in Medicare. If you can delay signing up for Medicare Parts A and B (see above), you can continue contributing to an HSA. Before you decide, determine whether the HSA’s tax breaks, any employer contributions and other benefits are more valuable than the premium-free Part A coverage.

Tip: Even if your Medicare premiums are automatically deducted from your Social Security check, you can take tax-free withdrawals from an HSA to reimburse yourself.

4. I have retiree health insurance. Do I need to sign up for Medicare at age 65? Unless you or your spouse is still working and has current employer coverage, you should sign up for both Medicare Part A and Part B at 65. Retiree coverage can fill gaps in Medicare (which would otherwise require Medigap and Part D policies or a Medicare Advantage plan), but it’s secondary to Medicare after age 65, and it may not kick in at all if you don’t sign up for Medicare. Federal retiree coverage is an exception; it remains your primary coverage if you don’t sign up for Medicare, but you will pay a penalty if you decide to sign up for Part B later.

5. What’s the penalty for not signing up? You’ll have to pay a late-enrollment penalty of 10% of the Medicare Part B premium for every year you should have had coverage. The penalty applies as long as you receive Medicare benefits. If you miss the initial enrollment period or the eight-month window after you or your spouse stops working, you can only sign up from January through March in any year for coverage to begin July 1.

Filling the Gaps

6. Why do I need Medigap insurance? You still have to pay deductibles and co-payments. Most people buy a Medicare supplement (Medigap) policy to pay those costs, plus Part D prescription-drug coverage because Medicare generally doesn’t cover drugs. Or you can sign up for a private Medicare Advantage plan, which provides both medical and drug coverage.

Medigap policies are sold by private insurers and come in 10 standardized versions (A through D; F; G; and K through N). Every Medigap plan with the same letter designation must provide the same coverage, even though prices can vary by insurer. You can use any doctor or facility that is covered by Medicare. You can search for Medigap price lists on the Medicare website.

Part D prescription-drug plans are sold by private insurers and have average premiums of $45.60 per month. You can compare premiums and out-of-pocket costs for your drugs under each Part D plan in your area.

Medicare Advantage plans combine medical and drug coverage and may also provide coverage that isn’t available through Medicare, such as for some dental and vision care. Premiums average $17.00 per month, which tends to be lower than for Medigap plus Part D, but you may have more out-of-pocket costs. The plans usually have a limited network of doctors and hospitals, and you may have higher costs (or no coverage) if you go out of network. You may also need a referral to see a specialist. You can shop for a Medicare Advantage plan by using your zip code. For an analysis of the best values based on typical costs for people in good, fair and poor health, at Medicare News Watch that features cost comparisons for over 200 Medicare health plans in 100 cities.

7. I’ve been paying high premiums for my Medigap Plan F. Can I switch to another policy to save money? Maybe. There’s a huge price range for Medigap policies, and you may be able to save by switching. But depending on your health and the state where you live, your options may be limited. Insurers cannot reject you or charge more because of preexisting conditions if you buy a Medigap policy within six months of signing up for Medicare Part B. But after that, your health can affect your costs and coverage options. If you’re still healthy, you may qualify for a better deal with another insurer.

Some insurers will let you switch to a less-comprehensive policy without medical underwriting — for example, to high-deductible Plan F, for which you pay a $2,870 deductible in 2025 before Medigap coverage kicks in. Median premiums are $768 per year for a 65-year-old man nonsmoker in Florida, compared with $5,532 for the standard Plan F, according to Investopedia. Plan N has coverage similar to that of standard Plan F, but you pay the Part B deductible ($257 in 2025) and a $20 co-payment for each physician visit, as well as $50 co-payment for emergency room visits. Average premiums are between $2,292 to $3,744 per year. Your state may offer special opportunities to switch, regardless of pre­existing conditions. For example, New Yorkers can switch Medigap policies at any time regardless of health. In Missouri, you can switch to another insurer’s version of your letter plan on your policy anniversary. (Learn more from your state health insurance assistance program website (SHIP) or call 800-633-4227 for contacts.)

8. The doctor I want to use isn’t covered by my Medicare Advantage plan. When can I switch to a different plan? You generally can’t switch to another Medicare Advantage plan until open enrollment in the fall, which runs from October 15 to December 7, 2024, for 2025 coverage. There are a few exceptions: You can switch plans if you qualify for a special enrollment period, such as if you move to an address that isn’t in your plan’s service area. You can also switch to a Medicare Advantage plan with a five-star quality rating anytime during the year. There are 31 five-star plans in the U.S. in 2024.

If you join a Medicare Advantage plan when you are first eligible for Medicare and switch back to traditional Medicare within 12 months, you can buy a Medigap policy and a Part D plan within 63 days of the change. Each year, you can switch from Medicare Advantage back to traditional Medicare and get a Part D drug plan from January 1 to February 14. But you could be rejected or charged more for Medigap because of a preexisting condition. For more about the rules, see Medicare Interactive.

Saving Money

9. How high must my income be to be snagged by the Medicare income-related monthly adjustment amount (IRMAA)? If the total of your adjusted gross income plus tax-exempt interest income is more than $106,000 if you’re single or $212,000 if you’re married and filing jointly, you have to pay extra for Part B, with monthly premiums of $185.00 to $628.90 in 2025, depending on your income. You’ll also have to pay an extra $13.70 to $85.50 each month for Part D drug coverage.

The high-income surcharge is based on your last tax return on file — for 2025 premiums, that’s your 2023 return. If your income has dropped since then because of certain life-changing events, such as divorce or retirement, you can appeal the IRMAA and ask the Social Security Administration to base premiums on your more recent income by filing Form SSA-44 and providing documentation.

Tip: Distributions from Roth IRAs and Roth 401(k)s will not be counted as income and will not trigger the IRMAA. Try to plan the conversion of a traditional IRA or 401(k) to a Roth version with sufficient leeway as to not trigger the IRMAA.

10. My doctor prescribed an expensive drug and even with my Part D coverage, I have to pay a lot of the cost out of pocket. What can I do to pay less? First, ask your doctor if you can use a generic drug or a “therapeutic alternative” that costs less under your plan. Also see if you can reduce co-pays by using a preferred pharmacy (ask your insurer which pharmacies are preferred). Then look for a new plan during open enrollment in the fall. Use the Medicare Plan Finder to compare premiums plus out-of-pocket costs for your drugs. See if there are restrictions, such as requiring prior authorization from your provider before covering pricey drugs, or step therapy, which means you have to try less-expensive drugs first, if possible.

11. After I’m on Medicare, can I use HSA money for medical expenses without paying taxes on it? Even though you can no longer contribute to an HSA after you sign up for Medicare, you can use money already in the account tax-free for medical expenses. You can also use the HSA money tax-free for Part B, Part D and Medicare Advantage premiums (but not Medigap).

Appealing Denied Claims

12. My Medicare claim was denied. What can I do? First find out why it was denied. It may be a coding error your doctor can fix and resubmit. Or Medicare may cover an expense but not submit the claim to your supplemental insurer, go to Medicare,gov to update this information. Drug coverage may be denied if you didn’t follow procedures for step therapy or prior authorization, but that denial may be reversed when you resubmit the forms.

If that doesn’t work, you have 120 days to appeal the denial. Look on the back of the Medicare summary notice for details, and the Medicare website for forms and more about each level of appeal. You have just 60 days to file an initial appeal for Medicare Advantage or Part D; follow the instructions on the explanation of benefits.

Tip: You can check the status of your appeal by logging into your Medicare.gov, account.

You can get help appealing a claim from your state health insurance assistance program (SHIP) or the Medicare Rights Center; 800-333-4114. Or use the Center for Medicare Advocacy’s appeal self-help packet.

Related Content

• What You Will Pay for Medicare in 2025
• Medicare Premiums 2025: IRMAA Brackets and Surcharges for Parts B and D
• How Medigap Insurance Is Affected by Preexisting Conditions
• What You Must Know About the Different Parts of Medicare
• You Missed Medicare Annual Open Enrollment — Now What?