What Medicare Is and Who Can Get It
Medicare is a federal health insurance program run by the Centers for Medicare & Medicaid Services (CMS). It covers people age 65 and older, some younger people with disabilities, and people with end-stage renal disease. You do not have to be retired to get Medicare — age 65 is the threshold, whether you are still working or not.
Medicare is not means-tested, which means your income or savings do not determine whether you can get it. If you have paid into Social Security through payroll taxes for at least 10 years (40 quarters), you are may have access to to Medicare Part A at no monthly premium when you turn 65. If you have not paid in long enough, you can still buy Part A, though the cost is higher.
Medicare is different from Medicaid, which is a separate program for people with lower incomes. Some people may have access to for both — this is called "dual may be able to access" status. If you are unsure which program covers you, your local Area Agency on Aging or your state Medicaid office can tell you.
Key Takeaways
- Medicare has four parts: Part A covers hospital stays, Part B covers doctor visits and outpatient care, Part D covers prescription drugs, and Part C (Medicare Advantage) is an alternative to Parts A and B offered by private insurers.
- You must enroll during your Initial Enrollment Period (the three months before, the month of, and the three months after your 65th birthday) or face permanent late penalties on Part B and Part D.
- Original Medicare (Parts A and B) has deductibles and coinsurance, so many people also buy Medigap (supplemental insurance) to cover those costs.
- You can change your Medicare coverage once a year during the Annual Enrollment Period (October 15 to December 7), or if you have a may have access to life event like moving or losing employer coverage.
- The official Medicare website (Medicare.gov) and 1-800-MEDICARE are free resources run by CMS; local Area Agencies on Aging also offer free, unbiased counseling.
The Four Parts of Medicare and What Each Covers
Part A covers inpatient hospital care, skilled nursing facility care (after a hospital stay), hospice, and some home health services. When you are admitted to a hospital, Part A pays most of the cost after you meet your deductible. In 2024, the Part A deductible is $1,632 per benefit period (a benefit period begins when you enter the hospital and ends 60 days after you leave). You pay coinsurance for days 61–90 and beyond.
Part B covers doctor visits, outpatient services, diagnostic tests, and preventive care like annual wellness visits and cancer screenings. Part B has a monthly premium (in 2024, the standard premium is $174.70 per month, though it varies by income). You also pay a yearly deductible ($240 in 2024) and then 20% coinsurance for most services after that.
Part D covers prescription drugs. It is offered by private insurance companies approved by Medicare, not by Medicare directly. Each plan has a different formulary (list of covered drugs) and different costs. You must enroll in Part D when you first become may be able to access, or you will pay a permanent penalty if you join later.
Part C, also called Medicare Advantage, is an alternative to Original Medicare (Parts A and B). Private insurers offer Part C plans that must cover everything Original Medicare covers, but they often add dental, vision, or hearing benefits. Part C plans usually have lower premiums and out-of-pocket limits than Original Medicare plus Medigap, but they restrict you to a network of doctors and often require prior authorization for services.
When and How to Enroll in Medicare
Your Initial Enrollment Period is seven months long: the three months before your 65th birthday, the month you turn 65, and the three months after. You should enroll during this window. If you miss it and do not have may have access to circumstances (such as employer coverage or disability), you will pay a permanent 10% penalty on Part B premiums for as long as you have Medicare. Part D has a similar permanent penalty if you delay.
You can enroll online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. If you are already receiving Social Security benefits, you may be enrolled automatically in Parts A and B, though you should confirm this and make choices about Part D and Part C.
After your Initial Enrollment Period, you can change your coverage during the Annual Enrollment Period, which runs from October 15 to December 7 each year. Changes take effect January 1. You can also change coverage if you have a may have access to life event — moving to a new state, losing employer coverage, getting married or divorced, or becoming may be able to access for Medicaid or Extra Help (a program that helps pay Part D costs).
Original Medicare Versus Medicare Advantage
Original Medicare (Parts A and B) lets you see any doctor or hospital that accepts Medicare. You pay deductibles and coinsurance, but there is no network restriction. Many people with Original Medicare also buy Medigap (supplemental insurance) to cover the deductibles and coinsurance that Original Medicare does not pay. Medigap plans are standardized — Plan G covers the same things whether you buy it from Aetna or Blue Cross — so you can compare by price alone.
Medicare Advantage plans are offered by private insurers and usually cost less in monthly premiums. They often include dental, vision, and hearing coverage that Original Medicare does not. However, you must use doctors and hospitals in the plan's network (except in emergencies), and many services require prior authorization. If you see an out-of-network doctor, you may pay the full cost.
Neither choice is right for everyone. Original Medicare plus Medigap gives you more freedom but higher upfront costs. Medicare Advantage limits your choices but may save money if you are healthy and willing to use the network. Your decision should depend on which doctors you want to see, how much medical care you expect to need, and your budget.
Prescription Drug Coverage Under Part D
Part D is offered by private insurance companies, not by Medicare itself. Each plan has a different list of covered drugs (formulary), different copays and coinsurance, and different monthly premiums. You choose a plan during your Initial Enrollment Period or during the Annual Enrollment Period.
Part D has a standard structure: you pay a monthly premium, then a deductible (up to $545 in 2024), then copays or coinsurance for each drug until you reach the out-of-pocket limit (around $8,850 in 2024). After that, you pay a small copay for the rest of the year. This structure means costs are highest in the middle of the year — a gap sometimes called the "donut hole," though the gap is smaller now than it used to be.
If your income is low, you may may have access to for Extra Help, a federal program that pays Part D premiums and reduces your copays. You can explore through Social Security or at your state Medicaid office. If you are already on Medicaid, you may be enrolled in Extra Help automatically.
Costs You Should Know About
Medicare is not free. Part A is free if you have paid into Social Security long enough, but Part B, Part D, and Medigap all have monthly premiums. Part A and Part B also have deductibles and coinsurance. The table below shows 2024 costs, but these amounts change each year.
| Part | Monthly Premium | Deductible | Coinsurance |
|---|---|---|---|
| Part A | $0 (if may be able to access) | $1,632 per benefit period | 20% after deductible for days 61–90 |
| Part B | $174.70 (standard) | $240 | 20% after deductible |
| Part D | Varies by plan | Up to $545 | Varies by plan |
| Medigap | Varies by plan and insurer | None | Depends on plan |
Your actual costs depend on which plan you choose, your income (higher earners pay more for Part B and Part D), and how much medical care you use. If you have limited income, you may may have access to for Medicaid, Extra Help, or the Medicare Savings Program, which helps pay premiums and cost-sharing.
Where to Get Help Understanding Your Options
Medicare.gov is the official source for information about plans, coverage, and enrollment. You can use the Plan Finder tool to compare Part D plans and Medicare Advantage plans side by side. The site also has videos, fact sheets, and a searchable database of participating doctors and hospitals.
1-800-MEDICARE (1-800-633-4227) is a free phone line run by CMS. Representatives can answer questions about coverage, help you enroll, and connect you to local resources. The line is open 24 hours a day, seven days a week.
Your local Area Agency on Aging offers free, unbiased counseling through a program called State Health Insurance information Program (SHIP). SHIP counselors can explain your options, help you compare plans, and answer questions about costs. To find your local SHIP, search "SHIP" plus your state name, or call the Eldercare Locator at 1-800-677-1116.
Frequently Asked Questions
What happens if I do not enroll in Medicare when I turn 65?
If you do not enroll during your Initial Enrollment Period and do not have a may have access to reason (such as employer coverage), you will pay a permanent 10% penalty on your Part B premium for as long as you have Medicare. Part D has a similar permanent penalty. You can still enroll after your Initial Enrollment Period, but the penalties explore when ready.
Can I keep my employer health insurance after I turn 65?
Yes, if your employer has 20 or more employees and still offers coverage to retirees. You can delay enrolling in Medicare without penalty as long as you have employer coverage. When you leave that job or the coverage ends, you have eight months to enroll in Medicare without penalty. Tell your employer's benefits office that you are turning 65 so they can explain your options.
What is the difference between Medicare and Medicaid?
Medicare is a federal program based on age (65+) or disability, not income. Medicaid is a joint federal-state program for people with lower incomes. Some people may have access to for both. If you are unsure which program covers you, call your state Medicaid office or your local Area Agency on Aging.
Can I change my Medicare plan if I realize I chose the wrong one?
You can change your plan once a year during the Annual Enrollment Period (October 15 to December 7). If you have a may have access to life event — such as moving, losing coverage, or becoming may be able to access for Medicaid — you can change plans outside the Annual Enrollment Period. Contact Medicare.gov or 1-800-MEDICARE to report a may have access to event.
Do I have to buy Medigap if I have Original Medicare?
No, Medigap is optional. Original Medicare covers a significant portion of your costs, but you will pay deductibles and coinsurance. Medigap covers some or all of those costs, depending on the plan. If you cannot afford Medigap, you may may have access to for the Medicare Savings Program, which helps pay Part A and Part B costs.