The four parts of Medicare are:

  • Part A – hospital coverage
  • Part B – doctors and outpatient services
  • Part C – Medicare Advantage
  • Part D – prescription drugs

In this article, we take a closer look at Medicare Part B and Part C. Read on to learn more about each plan, what they cover, and who’s eligible to enroll.

The two primary differences between Medicare parts B and C are:

  1. Part B is a key component of original Medicare, along with Part A. Part C is a bundling of components, including Part A, Part B, and often Part D.
  2. Part C is offered by private companies (approved by Medicare), while Part B is a government program administered by the Centers for Medicare and Medicaid Services (CMS).

Medicare Part B covers visits with your doctor and other outpatient services, such as:

  • diagnostic screenings
  • lab tests
  • medical equipment
  • ambulance

Medicare Part B also covers many preventive services, such as:


You’re eligible for Medicare Part B if you’re:

  • eligible for premium-free Medicare Part A
  • 65 years old or older
  • a U.S. citizen or a permanent legal resident living in the United States for a minimum of 5 continuous years

If you’re not 65 years old, you may be eligible if you:

Medicare Part C (Medicare Advantage) bundlestogether the primary components of Medicare into one comprehensive plan,including:

  • Medicare Part A
  • Medicare Part B
  • Medicare Part D (in most cases)

Some Medicare Advantage plans also offeradditional coverage, such as

Medicare Advantage plans offer different groups of services and benefits, so it’s important to read and compare plan descriptions.

When comparing plans, one difference might be HMO vs. PPO. This can affect doctor selection:

  • HMO (health maintenance organization). In an HMO plan, you typically choose a primary care doctor, and they must provide a referral for you to see a specialist.
  • PPO (preferred provider organization). In a PPO plan, you typically have a network of doctors and facilities to choose from, often not requiring primary care doctor referrals.

If you determine that Medicare Advantage isthe best choice for you:

  • You’re still required to enroll in Medicare parts A and B.
  • You’ll be required to pay the Part B premium if your plan doesn’t cover it.
  • Your Medicare Advantage plan’s premiums, deductibles, and services can change annually.


If you’re enrolled in original Medicare (Part A and Part B), you’re eligible to sign up for a Medicare Advantage plan.

Medicare Parts B and C have important differences. Medicare Part B is offered by the U.S. government to help cover the costs of doctor visits and outpatient services.

Medicare Part C is offered by private companies. It includes Medicare Part B along with Part A and often Part D. Medicare Part C can also include services not offered by Medicare, such as vision and dental.