When I first started my career in the Medicare world, I realized there was a lot of new information I had to learn and found that breaking it down into bite-sized chunks made it much easier to understand. I started by focusing on all the different parts of Medicare.

Here is a breakdown of what I learned to help you understand how Medicare works.

What is Medicare?

Simply put, Medicare is a federal health insurance program for:

  • People 65 and older
  • People under 65 with certain disabilities
  • People with end-stage renal disease

The Medicare program offers basic coverage to help pay for things like doctor visits, hospital stays and surgeries.

When you’re eligible, you can enroll in Medicare Parts A and B, also known as Original Medicare, through the Social Security Administration (SSA). This can be confusing for some – why does the SSA handle Medicare? Does that make Social Security benefits and Medicare the same? No, Social Security and Medicare have key differences and eligibility varies, but these two benefit programs can impact each other. For instance, if you are already receiving Social Security or Railroad Retirement Board benefits you’ll automatically be enrolled in Medicare.

Original Medicare covers the essentials, but there are a lot of services that aren’t included – important things like prescription drug coverage, annual hearing and routine eye exams, care needed when traveling outside the United States and much more. Services like these can be covered through private Medicare health plans and Medicare Part D prescription drug plans.

There are a few different times you can enroll in Medicare and a Medicare plan throughout the year. These are called enrollment periods.

Check out the graphic below to see when you can enroll, or read the article When and how to apply for Medicare for more in-depth info.

What are the 4 parts of Medicare?

Medicare is broken out into four parts.

  1. Medicare Part A – Hospital Coverage
  2. Medicare Part B – Medical Coverage
  3. Medicare Part C – Medicare Advantage
  4. Medicare Part D – Prescription Drug Coverage

The parts of Medicare cover different services:

What does Medicare Part A cover?

Part A (hospital coverage) covers things like inpatient hospital stays, home health care and some skilled nursing facility care. Together, Medicare Parts A and B are called Original Medicare.

Is Medicare Part A free?

Typically, most people don’t pay for Part A if they have paid Medicare taxes for a certain amount of time while working. However, if you don't qualify for premium-free Part A, it can be purchased for a monthly premium. This amount may vary each year and is based on how long you or your spouse worked and paid Medicare taxes.

What does Medicare Part B cover?

Part B (medical coverage) covers things like doctor visits, outpatient services, X-rays and lab tests, and preventive screenings.

Do you need Medicare Part B?

The short answer is yes, especially if you’ll need the covered services mentioned above. However, if you have health insurance through a current job or are on your spouse’s active plan, you can delay your Medicare Part B enrollment without penalty. Once the spouse with employer coverage stops working – whether it’s you or your partner – you have eight months to sign up for Part B. Also, you need to be enrolled in Medicare Part B if you want to sign up for a Medicare Advantage plan.

What does Medicare Part C cover?

Part C is also known as Medicare Advantage. Private health insurance companies offer these plans. When you join a Medicare Advantage plan, you still have Medicare. The difference is the plan covers and pays for your services instead of Original Medicare. These plans must provide the same coverage as Original Medicare (so you’re not missing out on anything). They can also offer extra benefits.

Why do I need to buy a private health plan?

Private Medicare health plans – like Medicare Advantage or Medicare Cost plans – cover everything Original Medicare does, and usually include more coverage for services you might need. Plus, they can include extra perks and benefits.

What does Medicare Part D cover?

Part D covers prescription drugs. Only private insurance plans offer it. It’s usually included in a Medicare Advantage plan or you can get a separate Part D plan.

Though Medicare Part B does cover certain vaccines and medications (based on specific health conditions), Part D provides a much wider range of coverage of vaccines and outpatient prescription drugs.

Read more: Does Medicare cover all of my vaccines?

Common services that Medicare does and doesn’t cover

Here’s general info about what Medicare does or doesn’t cover for common health care needs. Visit medicare.gov/coverage for more detail. Also, check a Medicare health plan’s Summary of Benefits to learn what’s covered.

Medicare has some coverage for acupuncture and it is limited to treatment of chronic low back pain. Some Medicare Advantage plans have benefits that help pay for acupuncture services beyond Medicare such as treatment of chronic pain in other parts of the body, headaches and nausea.

Assisted living is housing where people get help with daily activities like personal care or housekeeping. Medicare doesn’t cover costs to live in an assisted living facility or a nursing home.

Medicare Part A may cover care in a skilled nursing facility if it is medically necessary. This is usually short term for recovery from an illness or injury.

The federal Medicaid program can help pay costs for nursing homes or services to help with daily living activities.

Medicare Part B covers outpatient surgery to correct cataracts. It also pays for corrective lenses if an intraocular lens was implanted. Coverage is one pair of standard frame eyeglasses or contact lenses as needed after the surgery.

Medicare Part B covers a chiropractor’s manual alignment of the spine when one or more bones are out of position. Medicare doesn’t cover other chiropractic tests or services like X-rays, massage therapy or acupuncture.

Some Medicare Advantage plans have benefits that help pay for these other chiropractic tests or services.

Medicare covers 100% of the cost for screening colonoscopies. Test frequency depends on your risk for colorectal cancer:

  • Once every 24 months if you have a high risk
  • Once every 10 years if you aren’t at high risk; or every 48 months after a previous flexible sigmoidoscopy.

If during the colonoscopy a polyp or other tissue is found and removed, Medicare applies additional cost sharing for colorectal surgery or other treatment.

Medicare doesn’t cover routine eye exams to check your vision. Medicare will cover eye exams for those with diabetes or other medical conditions like glaucoma or cataracts.

Many Medicare Advantage plans have benefits that help pay for routine eye exams.

Medicare generally doesn’t cover eyeglasses or contact lenses. Part B does pay for eyeglasses or contact lenses if you need them after cataract surgery.

Many Medicare Advantage plans have benefits that help pay for eyeglasses and/or contact lenses you need to correct your vision.

Medicare doesn’t cover hearing aids or pay for exams to fit hearing aids. Some Medicare Advantage plans have benefits that help pay for hearing aids and fitting exams.

Medicare Part A and Part B cover some home health services if you meet certain conditions. Covered services include:

  • Skilled nursing care or home health aide services that are part-time or occasional (intermittent)
  • Physical, occupational or speech therapy
  • Medical social services

Medicare doesn’t cover 24-hour home care, delivered meals, homemaker services, or personal care. Some Medicare Advantage plans have benefits that help pay for the home health care services Medicare doesn’t cover and they may be limited to certain health conditions.

Medicare Part A covers hospice care for terminally ill patients who will live six months or less. Patients agree to receive services that focus on providing comfort instead of curing the disease. Coverage includes items and services for pain relief and symptom management, nursing and social services, drugs for pain management, aide and homemaker services, and spiritual counseling.

Medicare Part B covers outpatient physical therapy, speech-language pathology and occupational therapy services if it is medically necessary.

What isn’t covered by Medicare?

Original Medicare covers the essentials, but there are a lot of services that aren’t covered such as:

  • Deductibles, coinsurance and copays for covered services
  • Most dental care
  • Most outpatient prescription medicines
  • Routine eye exams
  • Routine hearing exams
  • Hearing aids
  • Fitness programs
  • Services outside the U.S.

Services like these can be covered through a private Medicare plan.