Medicare coverage through the federal government is known as Original Medicare. It includes insurance to cover hospital stays and doctor visits. You can choose to purchase additional coverage separately.

Comparable Medicare coverage through a private company such as Aetna is called Medicare Advantage. It includes hospital insurance, medical insurance and may have coverage for additional benefits you can’t get with Original Medicare.

Insurance companies negotiate discounted rates with groups of doctors, hospitals and other health care providers. These groups are known as networks. Some plans require you to use a doctor or hospital in its network. Going to a provider outside the network may cost you more.

Medicare may impose a penalty on prescription drug plan premiums if you don’t enroll during your initial enrollment period. 

Out-of-pocket costs are expenses that you must pay for Medicare-covered services. These costs depend on the type of coverage you have. They can include premiums, copayments, coinsurance and deductibles.