Part A helps cover inpatient hospital care and certain other services. Part B helps cover doctors’ services, outpatient care, and many preventive services. Together, Parts A and B are called Original Medicare. Part D provides prescription drug coverage through private plans. [1]

Medicare Advantage, also called Part C, is a way to receive Part A and Part B benefits through a Medicare-approved private plan; most plans include drug coverage. Medigap is supplemental insurance that can help pay some of your costs under Original Medicare. It is not used to cover costs under a Medicare Advantage plan. [1, 3]

For most people, the first opportunity to enroll begins three months before the month they turn 65 and ends three months after that month. This seven-month period is called the Initial Enrollment Period. Enrolling later can lead to a gap in coverage or a late-enrollment penalty if you do not qualify for another enrollment period. [2]

The answer can be different if you or your spouse still works and you have qualifying employer coverage. Review your specific coverage and enrollment dates before deciding to delay any part of Medicare. [2, 4]

Possibly. Coverage based on current employment may allow you to delay Part B and use a Special Enrollment Period later. When the employment or qualifying coverage ends, an eight-month Part B Special Enrollment Period generally applies. [4]

The size of the employer and the way the health plan coordinates with Medicare can affect which coverage pays first. Ask the employer’s benefits administrator and the insurer how the plan works for someone who is Medicare-eligible. Retiree coverage and COBRA are not the same as coverage based on current employment for this purpose. [4, 5]

With Original Medicare, you can generally use any doctor or hospital in the United States that accepts Medicare. You can add a separate Part D plan and, if eligible, purchase Medigap coverage to help with certain out-of-pocket costs. Original Medicare itself does not have an annual out-of-pocket maximum. [3]

Medicare Advantage plans are offered by private insurers. They generally use provider networks and have an annual limit on out-of-pocket costs for covered Medicare services. Many include drug coverage and additional benefits, but provider access, prior authorization requirements, and costs vary by plan. Compare the specific plans available where you live. [3]

Start with your doctors, hospitals, prescriptions, and expected services. Confirm whether providers participate, whether each medication is covered, and what you may pay in premiums, deductibles, copays, and coinsurance. A low monthly premium does not necessarily mean a low total annual cost. [3]

Also consider travel, a possible move, and how much flexibility you want when seeking care. Review the actual plan documents and current-year information; coverage and costs can change. [3, 6]

If you choose Original Medicare, a Medigap policy may help pay certain costs that Original Medicare leaves to you. Federal law provides a six-month Medigap Open Enrollment Period that generally begins the first month you are 65 or older and enrolled in Part B. During that period, you have important protections when buying a policy. [7]

Outside that window, obtaining or changing Medigap coverage can be more difficult unless another protection applies. Consider the timing of Part B and Medigap together rather than assuming you can purchase the same coverage on the same terms at any time. [7]

Plan for premiums and for costs when you use care, including deductibles, copays, coinsurance, and prescription costs. The amounts depend on your coverage choices and can change over time. [1, 3]

Also make room for services your plan may not cover. Original Medicare generally does not cover most routine dental care, hearing aids, or non-medical long-term care. Other coverage may help with some of these expenses, so check the terms of the coverage you select. [8]

Yes. People above certain income thresholds can owe an income-related monthly adjustment amount, commonly called IRMAA, in addition to their Part B and/or Part D costs. Social Security generally uses tax information from two years before the premium year to determine whether IRMAA applies. [9]

A Roth conversion, a large retirement-account withdrawal, or realized investment gains may affect the income used for this calculation. Consider the possible premium effect when making tax decisions. If your income later falls because of a qualifying life-changing event, you may be able to ask Social Security for a new determination. [9]

Medicare may cover certain medically necessary skilled services when its requirements are met, but it generally does not pay for long-term custodial care, such as ongoing help with bathing, dressing, or eating. That distinction matters whether care is provided at home or in a facility. [10]

Long-term care planning is a separate financial conversation. Consider possible care costs, family support, available savings, and any insurance coverage you already have rather than assuming Medicare will cover an extended stay. [10]

Once you are enrolled in Medicare, you are no longer eligible to make HSA contributions for the months of Medicare coverage. Medicare Part A enrollment can be retroactive when you sign up after age 65, potentially making recent HSA contributions excess contributions. [4, 11]

If you are still working and contributing to an HSA, coordinate the contribution stop date with your intended Medicare and Social Security enrollment dates. Existing HSA money can still be used for eligible expenses under the applicable HSA rules. [4, 11]

Do not assume so. COBRA is continuation coverage after employment or another qualifying event; it generally does not extend the eight-month Part B Special Enrollment Period tied to current employment. Medicare also warns that COBRA may pay only a small portion of costs if you are Medicare-eligible but not enrolled. [5]

Before choosing COBRA, confirm when your current-employment coverage ended, when your Part B enrollment period expires, and how the two coverages would coordinate. [5]

Yes. Health and drug plans can change their premiums, provider networks, drug formularies, and cost sharing. Your prescriptions and healthcare needs can change too. Medicare’s annual Open Enrollment Period generally runs from October 15 through December 7 for changes to eligible Medicare health and drug coverage. [6]

Review your plan’s Annual Notice of Change and compare the coming year’s options. If you have employer or retiree coverage, check with the benefits administrator before changing plans so you understand any effect on that coverage. [6]