The term “Original Medicare” refers to Medicare Part A and Part B. Part A helps cover the cost of hospital-related care, including inpatient services, lab tests and surgery. Part B is the medical insurance component of Medicare, which helps cover doctor visits, outpatient care and certain preventive services. The federal government administers both Part A and Part B.

Medicare Advantage plans are offered by private insurance companies—like Humana, Aetna, United Health Care—contracted by the federal government. Medicare Advantage, also referred to as Medicare Part C, covers the same healthcare services as Original Medicare, except for hospice care. Many Medicare Advantage plans also include prescription drug coverage.

Medicare costs consist of a monthly premium for Medicare coverage and a portion of the costs of covered services. There is no yearly limit on out-of-pocket expenses unless you have a Medicare Advantage plan.

TRICARE For Life may work with Original Medicare (Parts A & B), a Medicare Advantage plan or a Part D prescription drug plan. However, you may want to think carefully about whether you need Medicare drug coverage. TRICARE For Life includes a prescription drug benefit, so you may not need Part D. If you have TRICARE For Life and decide you want to enroll in Part D coverage, you can do it at any time. The TRICARE drug benefit is considered “creditable coverage,” which means it is at least as good as Medicare Part D. This allows you to sign up without paying the Part D late enrollment penalty. When you have TRICARE For Life and Medicare, you won’t receive a TRICARE wallet card. You only need your Medicare plan card and military ID as proof of coverage.

Medicare Supplement Insurance, also known as Medigap, is private health insurance that adds on to Original Medicare (Part A and B). It helps pay about 20% of the Medicare expenses that Original Medicare doesn't cover.