Medicare starts automatically at 65 if you have worked and paid taxes, but you still need to understand what it covers and what it does not
Medicare is federal health insurance that begins the month you turn 65. If you have worked in the United States for at least 10 years and paid Medicare taxes, you are covered automatically — you do not have to do anything to get Part A (hospital insurance). Part B (doctor visits and outpatient care) also starts automatically unless you turn it down in writing. You will receive a Medicare card in the mail about three months before your 65th birthday.
Medicare has four parts, and understanding what each one covers helps you know what bills you will and will not owe. Part A covers hospital stays, skilled nursing care after hospitalization, hospice, and some home health services. Part B covers doctor visits, lab work, imaging, and outpatient procedures. Part D covers prescription drugs. Part C, called Medicare Advantage, is an alternative way to get Parts A and B through a private insurance company, usually with lower out-of-pocket costs but a smaller network of doctors.
You will still pay money out of your pocket. Medicare does not cover everything, and you will have deductibles, copayments, and coinsurance. Many seniors buy a Medigap policy (supplemental insurance) to cover what Medicare leaves behind, or they choose a Medicare Advantage plan that bundles coverage differently. Understanding these choices before your 65th birthday makes enrollment simpler and helps you avoid penalties.
Key Takeaways
- Medicare Part A (hospital) starts automatically at 65 if you have worked and paid taxes for at least 10 years; Part B (doctor visits) also starts automatically unless you decline it.
- You will receive a Medicare card about three months before your 65th birthday; keep it safe because you will need it to see doctors and fill prescriptions.
- Medicare has out-of-pocket costs including deductibles and copayments, so many seniors buy a Medigap policy or choose a Medicare Advantage plan to reduce what they pay.
- If you do not sign up for Part B or Part D when you first become may be able to access, you may pay a permanent penalty on your premiums for as long as you have Medicare.
- Your coverage choices must be made during your initial enrollment period, which runs from three months before your 65th birthday through three months after.
What Medicare Part A covers and what you pay
Part A covers hospital inpatient stays, including room, meals, and nursing care. It also covers up to 100 days in a skilled nursing facility (a facility that provides medical care after you leave the hospital), hospice care, and some home health services. If you need a hospital stay, Part A pays most of the bill after you meet your deductible.
In 2024, the Part A deductible is $1,676 per benefit period — a benefit period begins when you enter the hospital and ends 60 days after you leave. If you are readmitted within that 60-day window, you do not pay another deductible. After you meet the deductible, Medicare pays all covered hospital costs for days 1 through 60. For days 61 through 90, you pay a daily coinsurance amount (in 2024, $419 per day). Part A does not cover private rooms, private nurses, or most prescription drugs you take at home.
Part A is funded through payroll taxes, so most people do not pay a monthly premium for it. However, if you did not work long enough to may have access to for free Part A, you can buy it. The premium varies depending on how many years you worked, ranging from roughly $278 to $556 per month in 2024.
What Medicare Part B covers and what you pay
Part B covers doctor visits, preventive care (like annual wellness visits and screenings), lab work, imaging, outpatient surgery, and durable medical equipment like wheelchairs and oxygen. It also covers mental health services, physical therapy, and some home health services. Part B is the insurance you use when you see your primary care doctor or a specialist in their office.
Part B has a monthly premium that most people pay. In 2024, the standard premium is $164.90 per month, though higher-income seniors pay more. You also pay an annual deductible ($240 in 2024), and after you meet it, you typically pay 20 percent of the cost of covered services. Your doctor's office bills Medicare first, and then you receive a bill for your share.
Part B does not cover routine dental care, vision exams for glasses or contacts, hearing aids, or most preventive care that is not on Medicare's list of covered screenings. It also does not cover care you receive outside the United States, except in limited circumstances near the U.S. border or on a cruise ship within U.S. territorial waters.
Part D prescription drug coverage and how to choose a plan
Part D is prescription drug insurance run by private companies under contract with Medicare. It is not automatic — you must choose a plan and enroll during your initial enrollment period or during the annual open enrollment period (October 15 through December 7 each year). If you do not sign up when you first become may be able to access and you go without coverage, you will pay a permanent penalty on your premiums for as long as you have Medicare, even if you sign up later.
Part D plans vary widely in which drugs they cover, how much you pay, and which pharmacies you can use. Each plan has a formulary — a list of covered drugs — and you can search plans on Medicare.gov to see whether your current medications are covered and at what cost. Plans are organized into tiers, and drugs on higher tiers cost you more. Most plans have a coverage gap (sometimes called the "donut hole") where your costs jump after you and your plan have spent a certain amount on drugs.
You can switch Part D plans once per year during open enrollment, so if your medications change or your costs go up, you can look for a better plan. Many seniors find it worth spending an hour comparing plans each fall, because switching can save hundreds of dollars per year.
Medigap policies: filling the gaps Medicare leaves
Medicare does not cover all medical costs. You will have deductibles, copayments, and coinsurance, and some services are not covered at all. A Medigap policy is supplemental insurance sold by private companies that pays some or all of these out-of-pocket costs. Medigap is different from Medicare Advantage — it works alongside Original Medicare (Parts A and B), not instead of it.
There are ten standardized Medigap plans, labeled A through N. Plan G and Plan N are the most common for people newly may be able to access for Medicare. Plan G covers most of what Medicare does not, including the Part B deductible, though it does not cover the Part A deductible. Plan N has lower premiums but requires you to pay copayments for some doctor visits and emergency room visits. You can compare plans on Medicare.gov or through your state health insurance counselor.
Medigap premiums vary by age, location, and the insurance company. You have the best rates if you buy a Medigap policy within six months of turning 65 and enrolling in Part B — this is called your open enrollment period for Medigap. If you wait longer, insurance companies can charge you more or deny you coverage based on your health. Once you have a Medigap policy, you can keep it for life as long as you pay the premiums, even if you move to a different state.
Medicare Advantage as an alternative to Original Medicare
Medicare Advantage (Part C) is an alternative way to get Medicare benefits. Instead of using Original Medicare (Parts A and B) plus a Medigap policy, you enroll in a private insurance plan that contracts with Medicare to provide all your Part A and Part B coverage. Most Medicare Advantage plans also include Part D drug coverage and dental or vision benefits that Original Medicare does not offer.
Medicare Advantage plans usually have lower or zero monthly premiums and lower out-of-pocket maximums than Original Medicare plus Medigap. However, they typically have a narrower network of doctors and hospitals, and you usually need a referral from your primary care doctor to see a specialist. If you travel frequently or live part of the year in another state, a Medicare Advantage plan may be restrictive because you can only see in-network doctors.
You can switch from Original Medicare to Medicare Advantage, or from one Medicare Advantage plan to another, during the annual open enrollment period (October 15 through December 7). If you switch to Medicare Advantage, you lose your Medigap policy — most insurance companies will not sell you one if you are enrolled in Medicare Advantage. If you later switch back to Original Medicare, you may not be able to buy a Medigap policy at the same price, depending on your age and health.
When to enroll and what happens if you miss the important date
Your initial enrollment period runs for seven months: three months before the month you turn 65, the month you turn 65, and three months after. During this window, you can enroll in Part B, choose a Part D plan, and buy a Medigap policy without penalties or waiting periods based on your health. If you are still working and covered by your employer's health plan, you may be able to delay enrollment without penalty, but you must notify Medicare in writing.
If you do not enroll in Part B during your initial enrollment period and you are not covered by an employer plan, you will pay a permanent penalty. The penalty is 10 percent of the Part B premium for each full year you were may be able to access but not enrolled. This penalty stays with you for life. The same rule applies to Part D — if you go without drug coverage and later enroll, you pay a penalty of 1 percent of the national average Part D premium for each month you were not covered.
If you miss your initial enrollment period, you can enroll during the general enrollment period (January 1 through March 31 each year), but coverage does not start until July 1, leaving you uninsured for several months. For this reason, it is important to mark your calendar and enroll before your important date passes.
Questions to ask your doctor and when to call Medicare
Before you turn 65, ask your current doctor whether they accept Medicare and what your out-of-pocket costs will be. Ask whether they are in-network for any Medicare Advantage plans you are considering. If you take prescription drugs, ask your pharmacist which Part D plans cover them and at what cost. These conversations take 15 minutes and can save you hundreds of dollars.
After you enroll, call Medicare (1-800-MEDICARE) if you have questions about your coverage, if you want to change your plan, or if you receive a bill you do not understand. You can also contact your State Health Insurance information Program (SHIP), a free counseling service that helps seniors understand Medicare. Find your state's SHIP by calling 1-877-839-2675 or visiting shiptalk.org.
Seek when ready care if you have chest pain, difficulty breathing, sudden weakness, or other signs of a medical emergency — do not wait to check your coverage. Go to the nearest emergency room or call 911. Medicare covers emergency care regardless of whether the hospital is in-network.
Frequently Asked Questions
Do I have to enroll in Medicare at 65 if I am still working?
If your employer has 20 or more employees and you are covered by their health plan, you can delay enrolling in Part B without penalty. However, you must still enroll in Part A at 65 because it is funded through taxes you have already paid. When you leave your job, you have eight months to enroll in Part B without penalty.
What if I move to another state after I enroll in Medicare?
Your Medicare coverage follows you anywhere in the United States. However, if you have a Medicare Advantage plan, check whether your doctors are in-network in your new state — you may need to switch plans. If you have a Medigap policy, it is portable, but you should contact your insurance company to make sure your coverage is active in your new location.
Can I change my mind about my coverage choices after I enroll?
Yes, but only during specific windows. You can change your Part D plan or Medicare Advantage plan once per year during open enrollment (October 15 through December 7). If you have a life-changing event like losing employer coverage or moving, you may have a special enrollment period that allows you to change plans outside the regular window.
Does Medicare cover dental, vision, or hearing care?
Original Medicare does not cover routine dental, vision, or hearing care. Some Medicare Advantage plans include these benefits, though usually with limits. You can also buy standalone dental, vision, or hearing insurance, or pay out of pocket. Ask your doctor for a referral to low-cost clinics in your area if cost is a barrier.
What if I cannot afford my Medicare premiums and out-of-pocket costs?
If your income is low, you may may have access to for programs that help pay your premiums and cost-sharing. The Medicare Savings Program helps pay Part B and Part D premiums. The Low-Income Subsidy program helps pay Part D costs. Contact your state Medicaid office or call 1-800-MEDICARE to learn whether you may have access to.