Medicare Advantage plans are sold by private insurance companies, not Medicare itself, and you join them during specific enrollment periods

A Medicare Advantage plan (also called Part C) is a way to get your Medicare coverage through a private insurer instead of through Original Medicare. The insurance company receives a payment from Medicare for each person enrolled, then provides hospital, doctor, and prescription drug coverage — often with lower out-of-pocket costs than Original Medicare, but with a network of doctors you must use.

You cannot straightforward call an insurance company and join whenever you want. Medicare has set enrollment windows when you can sign up. If you miss these windows and do not have a may have access to reason, you may have to wait until the next open period, which could be months away.

The three main enrollment periods are: Initial Enrollment Period (when you first turn 65), Annual Enrollment Period (October 15 to December 7 each year), and Special Enrollment Periods (if you lose coverage or move). Most people enroll during the Annual Enrollment Period.

Key Takeaways

  • You must be enrolled in Medicare Part A and Part B before you can join a Medicare Advantage plan.
  • The Annual Enrollment Period runs from October 15 to December 7 each year, and coverage starts January 1 if you enroll by December 7.
  • You can enroll directly through Medicare.gov, by phone at 1-800-MEDICARE, or through an insurance agent or broker.
  • Medicare Advantage plans vary by county, so the plans available to you depend on where you live.
  • You can switch to a different Medicare Advantage plan or back to Original Medicare once per year during the Annual Enrollment Period.

Check that you are enrolled in Medicare Part A and Part B first

Before you can join a Medicare Advantage plan, you must already have Medicare Part A (hospital insurance) and Medicare Part B (medical insurance). If you have not yet signed up for Medicare, you need to do that before you can enroll in a Medicare Advantage plan.

You can check your current Medicare enrollment status by logging into your account at Medicare.gov or by calling 1-800-MEDICARE. A representative can tell you whether Part A and Part B are active and when they started. If you are not yet enrolled, they can walk you through that process first.

Find plans available in your area

Medicare Advantage plans are not available everywhere. Each insurance company decides which counties and regions to serve, so the plans you can choose from depend entirely on your zip code. A plan available in one county may not be available in the next county over.

Go to Medicare.gov and use the "Find Care Providers and Suppliers" tool or the "Compare Medicare Advantage Plans" tool. Enter your zip code, and the site will show you every Medicare Advantage plan sold in your area. You will see the monthly premium, deductible, copays, and which doctors and hospitals are in the network for each plan.

If you do not have internet access, call 1-800-MEDICARE and a representative can read you the available plans and their details over the phone. This call is free.

Understand the costs and network before you choose

Medicare Advantage plans look different from Original Medicare. Instead of paying a deductible and then 20 percent of costs, you typically pay a monthly premium, a yearly deductible, and then copays (a set dollar amount per visit) or coinsurance (a percentage of the cost). Some plans have $0 monthly premiums but higher copays; others charge a premium but have lower out-of-pocket costs.

You must use doctors and hospitals in the plan's network, except in emergencies. If you go to an out-of-network provider, you will pay much more or the plan may not cover it at all. Before you enroll, check whether your current doctors are in the network. If your main doctor is not listed, call the plan to confirm, because the online directory is sometimes outdated.

Prescription drug coverage is included in most Medicare Advantage plans, so you do not need to buy a separate Part D plan. However, the drugs covered and the copays vary by plan, so check whether your medications are on the plan's formulary (the list of covered drugs) and at what cost.

Enroll during the Annual Enrollment Period or a Special Enrollment Period

The Annual Enrollment Period runs from October 15 to December 7 each year. If you enroll by December 7, your new plan coverage begins January 1. This is when most people switch plans or enroll for the first time.

If you are newly may be able to access for Medicare (turning 65 or becoming may be able to access due to disability), you have a three-month window called your Initial Enrollment Period. This runs from the month you turn 65 (or become may be able to access) through the two months after. You can enroll in a Medicare Advantage plan during this time without waiting for the Annual Enrollment Period.

A Special Enrollment Period allows you to enroll outside the normal windows if you have a may have access to life event — such as moving to a new state, losing employer coverage, or becoming a U.S. citizen. You typically have 60 days from the event to enroll. Call 1-800-MEDICARE to report your may have access to event and confirm your enrollment window.

Enroll through Medicare.gov, by phone, or with an agent

You have three ways to enroll in a Medicare Advantage plan:

  1. Medicare.gov: Log in to your account, go to "Enrollment and Plans," and select the plan you want. You will confirm your information and submit your enrollment. You should receive a confirmation email within a few minutes.
  2. 1-800-MEDICARE: Call this free number and a representative will help you compare plans and enroll over the phone. Have your Medicare card and Social Security number ready. The call typically takes 20 to 30 minutes.
  3. Insurance agent or broker: You can work with an agent who represents one or more insurance companies. Agents cannot charge you a fee — they are paid by the insurance company. You can find agents through Medicare.gov or by calling 1-800-MEDICARE for a referral.

Whichever method you use, you will need your Medicare number (on your Medicare card), your Social Security number, and your current mailing address. Enrollment is free.

Confirm your enrollment and understand your coverage start date

After you enroll, Medicare will send you a confirmation notice by mail within two weeks. This notice shows your plan name, your member ID number, and your coverage start date. Keep this notice in a safe place — you will need your member ID when you see a doctor or fill a prescription.

Your new plan coverage begins on the first day of the month after you enroll, or on January 1 if you enroll during the Annual Enrollment Period by December 7. Your old coverage ends on the last day of the month before your new coverage starts. During this transition, use your old insurance card until the new one arrives.

Your new insurance company will mail you a plan member ID card before your coverage starts. If you do not receive it by your start date, call the plan's customer service number (on your confirmation notice) to request a temporary card number you can use when ready.

What to ask your doctor and when to contact Medicare

Before your coverage starts, call your doctor's office and confirm they are in your new plan's network. Ask the staff to verify your coverage and whether you need a referral to see a specialist. Some Medicare Advantage plans require referrals; others do not.

Contact Medicare directly if: you enroll but do not receive a confirmation notice within two weeks; your new insurance card does not arrive before your coverage start date; you are unsure whether a doctor is in-network; or you want to change your plan after enrolling. Call 1-800-MEDICARE for any of these issues.

If you realize you chose the wrong plan after enrollment, you have until December 31 of that year to switch to a different Medicare Advantage plan or back to Original Medicare, as long as you are still within the Annual Enrollment Period. After December 7, you can only switch if you have a may have access to event.

Frequently Asked Questions

Can I enroll in a Medicare Advantage plan if I already have Original Medicare?

Yes. If you are already on Original Medicare, you can switch to a Medicare Advantage plan during the Annual Enrollment Period (October 15 to December 7) or if you have a may have access to event. When you enroll in a Medicare Advantage plan, your Original Medicare coverage ends automatically.

What happens if I miss the enrollment important date?

If you miss the Annual Enrollment Period and do not have a may have access to event, you cannot enroll in a Medicare Advantage plan until the next October 15. However, if you are newly may be able to access for Medicare (turning 65), you have a three-month Initial Enrollment Period. If you miss that window, you may face a late enrollment penalty when you eventually join.

Do I need to drop my Part D prescription drug plan before joining a Medicare Advantage plan?

Yes. Medicare Advantage plans include prescription drug coverage, so you cannot have both a Part D plan and a Medicare Advantage plan at the same time. When you enroll in a Medicare Advantage plan, your Part D coverage ends automatically. If you later switch back to Original Medicare, you will need to enroll in a Part D plan during the Annual Enrollment Period.

Can I switch Medicare Advantage plans in the middle of the year?

No, not unless you have a may have access to event such as moving, losing coverage, or becoming a U.S. citizen. Otherwise, you can only switch plans once per year during the Annual Enrollment Period (October 15 to December 7). Your new coverage would start January 1.

What if my doctor leaves the plan's network after I enroll?

If your doctor leaves the network, the plan must notify you. You can then switch to a different Medicare Advantage plan or back to Original Medicare outside the normal enrollment period. This is considered a may have access to event. Call your plan or 1-800-MEDICARE to report the change and request a Special Enrollment Period.