If you’ve just celebrated your 65th birthday or it’s coming up in the next year, your mailbox is probably full of postcards, flyers and letters about your eligibility for Medicare.
Before you sign up, though, you should explore the ins and outs of Medicare to ensure you’re finding the best plan for your needs while also avoiding unexpected costs. Even if you’ve been on Medicare for years, you should reevaluate your options annually to confirm that your plan is still the right choice for you.
In this guide, we outline everything you need to know about what Medicare is, how it works and when you can sign up.
[READ: Medicare Mistakes to Avoid.]
What Is Medicare?
Medicare is a federal health insurance program primarily for those age 65 and older. Medicare also covers those under age 65 with certain disabilities and conditions, such as end-stage renal disease or amyotrophic lateral sclerosis (also known as ALS or Lou Gehrig’s disease).
Medicare Plans and Coverage
There is a veritable alphabet soup of Medicare parts:
— Part A covers inpatient hospital, skilled nursing and hospice stays and some home health care.
— Part B covers visits to the doctor, preventive care, outpatient care, durable medical equipment and some home health care.
— Part D covers prescription drugs.
Together, Part A and Part B make up “original” or “traditional” Medicare.
How much does original Medicare cost?
How much you pay for each of these parts often changes from year to year.
| Part of Medicare | 2025 Costs | 2026 Costs |
| Part A | Premium: $0 (for 99% of beneficiaries) Deductible: $1,676 |
Premium: $0 (for 99% of beneficiaries) Deductible: $1,736 |
| Part B | Premium: $185 Deductible: $257 |
Premium: $202.90 Deductible: $283 |
| Part D | Premium: $36.78 Deductible: $590 |
Premium: $38.99 Deductible: $615 |
Original Medicare also does not provide a cap on out-of-pocket expenses for hospital or outpatient services (though the Part D cap mentioned below still applies if you’re enrolled in that plan).
[READ: First Medicare Bill Too High? Reasons Why and How to Fix It]
Medicare Advantage Plans
While Medicare parts A, B and D comprise the traditional framework, there’s an additional letter in the Medicare alphabet soup: Medicare Part C, also known as Medicare Advantage.
What is Medicare Advantage?
Medicare Advantage comprises health plans offered by private companies that contract with Medicare to provide you with all of your Part A and Part B benefits. Most plans also offer Part D drug coverage.
How much does Medicare Advantage cost?
What you pay for a Medicare Advantage plan often varies by region and the specific plan.
“Medicare Advantage plans can have low or no monthly premiums, but they usually require members to get their care only from network doctors and hospitals,” says Meredith Ramsey, an independent insurance agent in New Orleans. “Both options (original Medicare and Medicare Advantage) may have deductibles, copays and coinsurance, where you pay a percentage of the bill.”
For 2026, Medicare Advantage costs typically include:
— Monthly plan premium: About $14 per month in 2026, according to the Centers for Medicare & Medicaid Services (CMS). However, Medicare Advantage members must still pay their Part B premium.
— Maximum out-of-pocket limit: Up to $9,250 for in-network services
— Prescription drug cap: A separate $2,100 maximum out-of-pocket limit applied toward drug costs
What does Medicare Advantage cover?
Medicare Advantage plans provide the same coverage as original Medicare, as well as extra benefits — referred to as Medicare allowances — such as:
— Dental
— Vision
— Hearing
— Wellness coverage, such as gym memberships
— Over-the-counter drug coverage not provided in Part D
Plans can vary, though, so you’ll need to read the fine print to make sure your needs are covered.
What does Medicare Advantage not cover?
Medicare Advantage plans may have certain restrictions for covering medical care needed outside of the U.S. Make sure to review this benefit thoroughly before enrolling.
How to sign up for Medicare Advantage
You can sign up for a Medicare Advantage plan in several ways:
— Shopping online directly at U.S. News
— Partnering with an individual, licensed insurance agent, who can enroll you via a paper or electronic application
— Applying online at Medicare.gov
— Calling 1-800-MEDICARE (1-800-633-4227)
— Applying through a private insurer’s website (make sure to look for Medicare Advantage-specific plans)
[READ: What to Do if AI Denies Your Medicare Claim or Prior Authorization]
Medicare Supplement (Medigap) Plans
If you’re opting for original Medicare but may need additional financial assistance to pay for out-of-pocket costs, you might consider a Medicare supplement plan.
What is a Medicare supplement plan?
A Medicare supplement plan, also known as Medigap, is for people who have original Medicare but need another plan to help cover remaining costs associated with services received.
“You can go through your life with just parts A and B, but the out-of-pocket costs will get you,” notes Diane J. Omdahl, founder of 65 Incorporated, a Wisconsin-based company that helps people choose Medicare coverage.
Depending on where you live and when you’re eligible for Medicare, multiple types of Medigap policies, such as Plan G and Plan N, are offered by private insurers or via groups such as AARP.
How much does Medigap cost?
Medigap costs vary considerably depending on pricing models and other factors, but each plan — regardless of the company you buy it from — must offer the same services. In other words, Plan A at Company 1 will have the same coverage as Plan A at Company 2.
What does Medigap cover?
Medigap helps cover original Medicare-related costs, including:
— Deductibles
— Copayments
— Coinsurance
What does Medigap not cover?
Medigap doesn’t cover:
— Vision care and glasses
— Dental care
— Hearing aids
— Private nursing
— Long-term care, such as a nursing home
— Custodial care
How to sign up for Medigap
Before signing up for Medigap, make sure to do your research. The cost of Medigap plans can vary by state. Resources to help you include:
— Trusted sites, such as U.S. News, Medicare.gov and CMS.gov
— Licensed brokers or agents who offer Medigap plans
— Counselors with State Health Insurance Assistance Programs
— Medicare supplement websites, where you can search for plans by ZIP code
Once you’ve settled on a plan, you can fill out an application. Following approval, you should review the policy to make sure it’s still the right fit.
Medicare Eligibility and Enrollment Dates
Regardless of your retirement age, and if you qualify, you become eligible for Medicare when you turn 65. Once you’ve reached eligibility, there are multiple windows when you can enroll in Medicare.
Medicare initial enrollment
You can first sign up for Medicare or Medicare Advantage three months before your 65th birthday, during your birth month or throughout the three months after. During this window, known as the initial enrollment period, you can also enroll in a Medigap plan if you’ve also enrolled in Medicare Part B. (You can also sign up for Medigap after this period, but prices could be higher or your application could be denied due to major health issues you may have.) You have 60 days to sign up for a Medicare Part D prescription drug plan after this period.
You may face a long-term penalty if you don’t sign up during this seven-month window, even if you’re still working.
If you receive benefits from Social Security or the Railroad Retirement Board four months before your 65th birthday, you will be automatically enrolled in Medicare.
Medicare open enrollment
For those who aren’t enrolling for the first time, the open enrollment period, also known as the annual election period, runs from October 15 through December 7. During this period, you can:
— Review, adjust or switch your Medicare plan, including Medicare Part D or Medicare Advantage plans
— Enroll in a Medicare Advantage plan
— Drop a Medicare Advantage plan to return to original Medicare
Medicare Advantage open enrollment
Another open enrollment period, known as the Medicare Advantage open enrollment period, runs from January 1 through March 31. This period is for those already enrolled in a Medicare Advantage plan who want to switch to another Medicare Advantage plan or go back to original Medicare.
Medicare general enrollment
The general enrollment period, which lasts from January 1 through March 31, is for those who need to enroll in original Medicare but missed the initial enrollment window and don’t qualify for special enrollment. Your coverage starts the month after you sign up. You might pay a monthly late enrollment penalty if you don’t qualify for a special enrollment period.
Medicare special enrollment
If you need to enroll or adjust your coverage outside of the regular enrollment windows, you may qualify for a special enrollment period. Some example situations include:
— You lost Medicare or Medicaid coverage after January 1.
— You couldn’t enroll because of a natural disaster or an emergency that’s declared or starts on or after January 1.
— You’re volunteering and serving in another country.
— You were recently incarcerated and couldn’t sign up during your incarceration.
Depending on your situation, you may have up to six months to enroll in Medicare. If you don’t sign up within that window, you’ll have to wait for the general enrollment period and possibly pay a late enrollment penalty.
Medicare Savings Programs for Low-Income Seniors
Americans with very low incomes may be eligible for extra help with Medicare premiums and health care costs. The four primary Medicare Savings Programs are:
— The Qualified Medicare Beneficiary Program, which helps pay for premiums, deductibles, coinsurance, copayments and prescription drugs.
— The Specified Low-Income Medicare Beneficiary Program, which helps pay for Medicare Part B premiums and prescription drugs.
— The Qualifying Individual Program, which helps pay for Medicare Part B premiums.
— The Qualified Disabled Working Individual Program, which helps to pay Part A premiums only for those who have a disability, are working and lost their $0 premium Part A coverage because they chose to return to work.
More from U.S. News
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What Is Medicare: Coverage, Cost and Enrollment originally appeared on usnews.com
Update 06/30/26: This story was published at an earlier date and has been updated with new information.
