Medicare Guide

Medicare is federal health insurance for eligible people, including most people age 65 or older and some younger people with certain disabilities or conditions. The core program is organized around Part A and Part B. You can receive those benefits through Original Medicare or, if eligible, through a private Medicare Advantage plan. Prescription drug coverage and Medicare Supplement insurance are separate decisions.

Start with the four parts of Medicare

Part A — Hospital Insurance. Part A helps cover inpatient hospital care, skilled nursing facility care, hospice care, and some home health care.

Part B — Medical Insurance. Part B helps cover services from doctors and other health care providers, outpatient care, durable medical equipment, home health care, and many preventive services.

Part C — Medicare Advantage. Medicare Advantage plans are offered by Medicare-approved private companies. They provide Part A and Part B benefits and usually include Part D drug coverage. Plans can have provider networks, service-area rules, prior-authorization requirements, and different out-of-pocket costs.

Part D — Prescription Drug Coverage. Part D helps pay for covered prescription drugs. You can get drug coverage through a stand-alone Medicare drug plan or, in many cases, through a Medicare Advantage plan that includes Part D.

Medicare Supplement insurance, also called Medigap, is not a part of Medicare. It is private supplemental insurance designed to help pay certain out-of-pocket costs in Original Medicare.

Original Medicare or Medicare Advantage?

With Original Medicare, you generally can use any doctor or hospital in the United States that takes Medicare. Original Medicare does not have a general annual out-of-pocket maximum for Part A and Part B services. Some people add a stand-alone Part D plan and may buy a Medigap policy to help with eligible cost sharing.

Medicare Advantage is another way to receive Part A and Part B benefits. Plans must cover medically necessary services that Original Medicare covers, but they may use provider networks, referrals, and prior authorization. Plans may also offer benefits Original Medicare does not routinely cover. Every Medicare Advantage plan has an annual limit on what you pay out of pocket for covered Part A and Part B services.

Compare the two approaches based on your doctors, hospitals, prescriptions, travel needs, expected costs, and how much flexibility you want.

When should you enroll in Medicare?

For many people, the first opportunity to enroll is the seven-month Initial Enrollment Period surrounding the month they turn 65. Different rules can apply if you or your spouse are still working and have qualifying employer coverage. Missing the correct enrollment period can cause a coverage gap or a late-enrollment penalty.

After you have Medicare, separate enrollment periods control when you can join, switch, or leave Medicare Advantage and Part D plans. Special Enrollment Periods may apply after certain life events.

Before making a change, identify which enrollment period applies to you.

What does Medicare cost?

Medicare costs can include premiums, deductibles, copayments, and coinsurance. Part A is premium-free for many people based on work history, while Part B generally has a monthly premium. Medicare Advantage and Part D costs vary by plan. Medigap premiums vary by policy, insurer, location, and other permitted rating factors.

Because Medicare cost amounts can change each year, use the current official Medicare figures when estimating your expenses.

Help with Medicare costs

People with limited income and resources may qualify for programs that lower Medicare expenses. Medicare Savings Programs are administered by states and may help pay Part A or Part B premiums and, in some cases, Medicare deductibles, coinsurance, and copayments. Extra Help can reduce Medicare Part D drug costs.

If you have both Medicare and Medicaid, you are considered dually eligible. Your Medicaid benefits and available Medicare plan options can vary by state and by your eligibility category.

Medicare coverage decisions worth reviewing

A useful Medicare review usually includes:

your doctors and hospitals;
your prescription drugs and preferred pharmacies;
premiums and expected out-of-pocket costs;
whether you want Original Medicare or Medicare Advantage;
whether you need Part D coverage;
whether Medigap is available and appropriate for your situation;
your travel habits;
eligibility for Extra Help, Medicare Savings Programs, or Medicaid; and
the enrollment period that applies to you.

Explore Medicare topics

Learn more about Medicare Advantage plans, Medicare Part D, Medicare Supplement insurance, Medicare enrollment, Medicare versus Medicaid, Extra Help, Medicare Savings Programs, dual eligibility, home health coverage, and Medicare resources in your state.

Get help reviewing your Medicare options

Wise Owl Insurance Group provides Medicare education and licensed-agent assistance. Plan availability, benefits, premiums, provider networks, formularies, and eligibility vary by location, plan, and plan year.

Wise Owl Insurance Group is not connected with or endorsed by the U.S. government or the federal Medicare program. For official Medicare information, use Medicare.gov or call 1-800-MEDICARE.

Last reviewed: September 22, 2026.