Medicare Basics: 11 Things You Need to Know

Medicare basics include Parts A, B and D, Medigap plans, Medicare Advantage plans and more. We sort out the confusion.

Senior female patient understanding form filling procedure by receptionist through transparent shield in clinic
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Understanding Medicare basics may be one of the most maddening tasks you'll face when heading into retirement. Figuring out when to enroll in Medicare and which parts of Medicare to elect can be daunting even for the savviest retirees. 

There are Part A, Part B, Part D, Medigap plans, Medicare Advantage plans and so on. And what the heck is a doughnut hole, anyway? Medicare open enrollment runs annually from October 15 through Dec. 7 every year. You should understand the basics before you make any choices or changes.

So, to help you wade into the waters of this complicated federal health insurance program for retirement-age Americans, here are 11 essential things you must know about Medicare.

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1. Medicare comes with a cost

Medicare is divided into parts. Part A, which pays for hospital services, is free if you or your spouse paid Medicare payroll taxes for at least 10 years. People who aren't eligible for free Part A can pay a monthly premium of several hundred dollars. 

Part B covers doctor visits and outpatient services, and it comes with a price tag — the standard monthly premium in 2024 will be $174.70, up $9.80 from $164.90 in 2023.

Part D, which covers prescription drug costs, also has a monthly charge that varies depending on which plan you choose; the average Part D total premium for 2024 will be about $55.50 per month in 2024, down from $56.49 in 2023. In addition to premium costs, you'll also be subject to co-payments, deductibles and other out-of-pocket costs.

2. Fill Medicare's coverage gaps with a Medigap plan

Beneficiaries of traditional Medicare will likely want to sign up for a Medigap supplemental insurance plan offered by private insurance companies to help cover deductibles, co-payments and other gaps. You can switch Medigap plans at any time, but you could be charged more or denied coverage based on your health if you choose or change plans more than six months after you first signed up for Part B. 

Medigap policies are identified by letters A through N. Each policy that goes by the same letter must offer the same basic benefits, usually the only difference between same-letter policies is the cost. 

Plan F has been very popular because of its comprehensive coverage, but as of 2020, Plan F (along with Plan C) is unavailable for new enrollees. The closest substitute for Plan F is Plan G, which pays for everything that Plan F did except the Medicare Part B deductible. Anyone enrolled in Medicare before 2020 can still sign up for plans F and C.

3. Consider Medicare Advantage for all-in-one plans

A woman receives healthcare at home.

(Image credit: Getty Images)

You can choose to sign up for traditional Medicare: Parts A, B and D, and a supplemental Medigap policy. Or, you can go an alternative route by signing up for Medicare Advantage, which provides medical through private insurance companies. These plans also frequently include prescription drug coverage.

Also called Part C, Medicare Advantage has a monthly cost, in addition to the Part B premium, that varies depending on which plan you choose. For 2024, the average monthly premium for Advantage plans is $18.50, up from $18 in 2023.

Like traditional Medicare, you'll also be subject to co-payments, deductibles and other out-of-pocket costs. In many cases, Advantage policies charge lower premiums than Medigap plans but have higher cost-sharing. Your choice of providers may be more limited with Medicare Advantage than with traditional Medicare, and recent research has found that sicker enrollees often dump Medicare Advantage in favor of original Medicare.

4. High income earners pay more for Medicare

If your income is above a certain threshold, you'll pay more for Parts B and D. These income-related monthly adjustment amounts (IRMAA) are based on your adjusted gross income from two years earlier. In 2024, single filers with an adjusted gross income (AGI) from 2022 that exceeds $103,000 ($206,000 for married couples filing jointly) will pay a premium ranging from $244.60 to $594 per month, depending on their income. The standard premium will be $174.70.

For Part D coverage in 2024, single filers with an AGI from 2022 that exceeds $103,000 ($206,000 for married couples filing jointly) will pay an extra $12.90 to $81 per month, depending on their income.

5. When to sign up for Medicare

If you are already collecting Social Security benefits, you will be automatically enrolled in Parts A and B. You can choose to turn down Part B, since it has a monthly cost; if you keep it, the cost will be deducted from Social Security if you already claimed benefits.

You will have to sign yourself up for Parts A and B if you have not started Social Security. The seven-month initial enrollment period begins three months before the month you turn 65 and ends three months after your birthday month. Sign up in the first three months to ensure coverage starts by the time you turn 65.

You may be able to delay signing up for Medicare if you are still working and have health insurance through your employer (or if you’re covered by your working spouse’s employer coverage.) But you will need to follow the rules and must sign up for Medicare within eight months of losing your employer’s coverage to avoid significant penalties when you do eventually enroll.

6. A quartet of Medicare enrollment periods

Picture of a Medicare Card with the words "open enrollment"

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There are several other Medicare open enrollment periods, in addition to the seven-month initial enrollment period. 

If you missed signing up for Part B during that initial enrollment period and you aren't working (or aren't covered by your spouse's employer coverage), you can sign up for Part B during the general enrollment period that runs from Jan. 1 to March 31. Coverage will begin on July 1. But you will have to pay a 10% penalty for life for each 12-month period you delay in signing up for Part B. 

Those covered by a current employer's plan, though, can sign up later without penalty during a special enrollment period, which lasts for eight months after you lose that employer coverage. If you miss your special enrollment period, you must wait until the general enrollment period to sign up.

Open enrollment runs from Oct. 15 to Dec. 7 every year, during which you can change Part D plans or Medicare Advantage plans for the following year, or switch between Medicare Advantage and original Medicare. Advantage enrollees also can switch to a new Advantage plan or original Medicare between Jan. 1 and March 31. And if a Medicare Advantage plan or Part D plan available in your area has a five-star quality rating, you can switch to that plan outside of the open enrollment period.

7. A filled doughnut hole for Medicare Part D

In 2020 the dreaded Part D "doughnut hole" was filled. That hole is a coverage gap in which you used to face much higher out-of-pocket costs for your drugs, but that is no longer the case. For 2024, when the total amount you and your plan have paid for drugs reaches $5,030 then you will pay 25% of any additional costs. (This percentage used to be higher before the gap was closed.) Prescription drug manufacturers pick up 70% while insurers pay 5%.

Catastrophic coverage, with the government picking up most costs, begins when a patient's out-of-pocket costs reach $8,000, the maximum spending limit for beneficiaries in 2024. 

Any deductible paid before you entered the doughnut hole counts toward that annual maximum as does the 25% you contributed while in the doughnut hole and the 70% that pharmaceutical companies paid on your behalf.

8. Medicare offers more free preventive services

A man gets his blood pressure taken at the doctor.

(Image credit: Getty Images)

Medicare beneficiaries can receive a number of free preventive services. You get an annual free "wellness" visit to develop or update a personalized prevention plan. Beneficiaries also get a free cardiovascular screening every five years, annual mammograms, annual flu shots, and screenings for cervical, prostate and colorectal cancers.

9. Medicare expands telehealth offerings

Although most Medicare Advantage plans have been covering telehealth for years, traditional Medicare used to restrict the service only to certain devices and practitioners, and patients had to be at a Medicare facility. 

When the coronavirus pandemic hit, telehealth was expanded so that patients could use smartphones in their own homes to consult with a broader range of medical professionals. This feature has become permanent. 

10. What Medicare does not cover

While Medicare covers your healthcare, it generally does not cover long-term care — an important distinction. Under certain conditions, particularly after a hospitalization to treat an acute-care episode, Medicare will pay for medically necessary skilled nursing facility or home healthcare. 

But Medicare generally does not cover costs for "custodial care" — that is, care that helps you with activities of daily living, such as dressing and bathing. To cover those costs, you will have to rely on your savings, long-term-care insurance or Medicaid — if you meet the income and asset requirements. Traditional Medicare also doesn't cover routine dental or eye care and some items such as dentures or hearing aids.

11. You have the right to appeal a Medicare decision

If you disagree with a coverage or payment decision made by Medicare or a Medicare health plan, you can file an appeal. The appeals process has five levels, and you can generally go up a level if your appeal is denied at a previous level. 

Gather any information that may help your case from your doctor, healthcare provider or supplier. If you think your health would be seriously harmed by waiting for a decision, you can ask for a fast appeal to be made and if your doctor or Medicare plan agrees, the plan must decide your request within 72 hours.

Contact your State Health Insurance Assistance Program (SHIP) if you need help filing an appeal. 

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Managing Editor, Kiplinger's Retirement Report

Siskos is an old hat with the Kiplinger brand. More than a decade ago, she spent eight years writing about personal finance for Kiplinger's Personal Finance magazine, including a monthly column—Starting Out—that served young adults. That was in her salad days. Now she's turned her attention to an audience she hopes to join in a decade or so: retirees. Siskos is the managing editor for Kiplinger's Retirement Report. In between, she broadened her personal-finance repertoire with real estate and investing stories at Old-House Journal, Investing Daily and U.S. News. She comes to Kiplinger by way of the Newseum, where she worked as an exhibit editor.

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