If you have been paying into social security during your working life, and have met the minimum work amount requirements, you are eligible for medicare. Medicare insurance can be viewed as four parts.
Part A - Hospital Insurance
Part B - Medical Insurance
Part C - Medicare Advantage
Part D - Prescription Coverage
Medicare Part A - Hospital Insurance
Medicare Part A is the part of Medicare that everyone eligible receives. It covers inpatient hospital care, along with skilled nursing facility care, home health care and hospice facility care. It does not cover long term or custodial care. Most people do not have to pay a premium for this portion of coverage.
Medicare Part B - Medical Insurance
Medicare Part B is optional. The purpose of part B is to cover medically necessary services like doctors' services, diagnostic tests, outpatient care, physical therapy and some preventive screenings. These are services that Part A does not cover.
Part B is optional. If you are still working, your employer's insurance may cover this portion . If you are no longer insured by your employer, you will have to pay a premium to receive this coverage.
Medicare Part C - Medicare Advantage
Medicare Part C is the "private" portion of Medicare. In Part C, a private insurer has contracted with the government to take over the management of all of your Medicare benefits. You pay premiums directly to this private insurer. Your benefits are then all provided through this private insurer. That is the insurer and pays claims on your behalf.
Part C is optional and you still have to pay the Part B premium. The difference is that your benefits are provided by a private insurer and not the government.
Both Medicare Advantage and Medicare supplemental insurance covers the gaps left by the original coverage. You do not need both. The difference is that Medicare Advantage pays instead of Medicare, whereas supplements pay AFTER Medicare pays;
Medicare Part D - Prescription Coverage
Medicare Part D is the portion of the program which covers prescription drugs. It is offered through private companies. In order for a private company to provide this coverage, they must be certified and approved by the Centers for Medicare & Medicaid Services. This certification is renewed annually.
Part D is optional and requires you to pay a premium. This premium is paid directly to the private company and not the government.
If you need Medicare supplemental, Medicare Advantage, or Medicare Part D coverage, you can find many sources online. Read articles and follow the links in the article to find more information.