What matters most when you choose a Medicare plan

The right Medicare plan depends on three things: which doctors and hospitals you want to use, how much you can afford to pay each month, and how often you expect to need care. Medicare offers four main types of coverage — Original Medicare, Medicare Advantage, Medigap, and Part D — and each one works differently. You do not have to pick the same plan every year. Open enrollment runs from October 15 to December 7 each year, and you can switch plans during that window without penalty.

Start by listing the doctors and specialists you see regularly, then check whether they accept each plan you are considering. A plan that costs less per month but does not include your cardiologist or rheumatologist will cost you more in the long run. Next, estimate how many prescription drugs you take and what they cost under each plan's formulary — the list of covered medications. Finally, add up the monthly premium, deductible, copay, and coinsurance to see your total out-of-pocket risk in a typical year.

Key Takeaways

  • Original Medicare covers hospital and doctor visits nationwide but requires you to pay 20 percent coinsurance after the deductible, so most people add Medigap or Part D separately.
  • Medicare Advantage bundles hospital, doctor, and prescription coverage into one plan with a monthly premium and usually lower copays, but restricts you to in-network doctors except in emergencies.
  • Medigap is supplemental insurance that pays the coinsurance and deductible Original Medicare does not cover, and it works with any doctor who accepts Medicare.
  • You can compare plans side by side on Medicare.gov, and the tool shows you exactly which doctors and pharmacies are in each network before you enroll.
  • If you miss the October-December enrollment window, you can only switch plans if you have a may have access to life event like moving, losing other coverage, or turning 65.

Original Medicare versus Medicare Advantage: the core difference

Original Medicare is run by the federal government and covers hospital stays (Part A) and doctor visits (Part B) at any hospital or doctor's office in the United States that accepts Medicare. You pay a monthly premium for Part B, then you pay a deductible before coverage kicks in, and after that you pay 20 percent coinsurance on most services. Original Medicare does not cover prescription drugs, dental, vision, or hearing aids — you buy those separately or add Medigap.

Medicare Advantage is sold by private insurance companies and bundles hospital, doctor, and prescription coverage into one monthly premium. Most Advantage plans have a $0 or low monthly premium, lower copays than Original Medicare, and they include dental or vision benefits. The trade-off is that you must use doctors and hospitals in the plan's network, except in true emergencies. If you travel frequently or see specialists outside your area, Advantage may frustrate you. If you stay in one region and want predictable monthly costs, Advantage often costs less overall.

A third option is to choose Original Medicare and add Medigap (supplemental insurance) plus Part D (prescription coverage). Medigap pays the 20 percent coinsurance and deductible that Original Medicare leaves you responsible for, so your out-of-pocket costs become more predictable. This route costs more in monthly premiums but gives you the freedom to see any doctor who accepts Medicare anywhere in the country.

How to check if your doctors are in-network

Before you enroll in any plan, search for each of your regular doctors on Medicare.gov's plan finder tool. Enter your zip code, select the plans you are considering, and the tool will show you whether each doctor is in-network, out-of-network, or not listed. Call your doctor's office directly if the website shows "not listed" — sometimes the data lags behind reality. Ask whether they accept the specific plan you are thinking about, not just Medicare in general.

For specialists, search by name and specialty. If your cardiologist is out-of-network for a Medicare Advantage plan, ask whether they will refer you to an in-network cardiologist or whether you can see them out-of-network and pay more. Some Advantage plans allow out-of-network referrals for specialists you cannot find in-network, but the rules vary by plan and by state. Write down the answer so you have it in writing if you need to file a complaint later.

If you use a hospital for regular treatment — dialysis, chemotherapy, infusions — search for that hospital by name in the plan finder. Confirm it is in-network before you enroll. Switching hospitals mid-treatment because your new plan does not cover your old one creates real hardship.

Understanding prescription drug costs under each plan

Original Medicare does not cover prescription drugs. You must buy Part D (prescription coverage) separately from a private insurance company. Part D plans have different formularies — lists of covered drugs — and different copays for the same medication. A drug that costs $10 under one plan might cost $50 under another, so comparing formularies matters more than comparing monthly premiums.

Medicare Advantage plans include prescription coverage as part of the bundle, but the formulary and copays vary by plan. Use the plan finder on Medicare.gov to search for each of your regular medications and see what you would pay under each plan. If you take a brand-name drug that has a generic equivalent, the plan might require you to try the generic first before covering the brand name — this is called prior authorization. Ask the plan whether your current medications require prior authorization before you enroll.

Medigap does not cover prescription drugs. If you choose Original Medicare plus Medigap, you still need to buy Part D separately. You have a 63-day window after you turn 65 or lose other coverage to enroll in Part D without penalty. If you miss that window and go without Part D, you pay a permanent surcharge when you finally enroll — roughly 1 percent of the national average Part D premium for each month you were uninsured.

Calculating your total out-of-pocket costs

Do not compare plans based on monthly premium alone. Add up the monthly premium, annual deductible, copay per visit, and coinsurance percentage to estimate what you will actually pay in a typical year. For Original Medicare, the 2024 Part B premium is $164.90 per month, the deductible is $240 per year, and you pay 20 percent coinsurance after that. If you see a specialist who charges $200, you pay $40 after the deductible is met. If you need an MRI that costs $1,000, you pay $200.

For Medicare Advantage, the monthly premium might be $0, but the copay for a specialist visit might be $50 and the copay for an MRI might be $300. The plan has an out-of-pocket maximum — usually $6,700 to $7,500 per year — so once you hit that number, the plan covers everything else at no cost. Original Medicare has no out-of-pocket maximum, which is why most people on Original Medicare buy Medigap.

Use the plan finder on Medicare.gov to see the estimated costs for each plan based on your actual doctors and medications. The tool shows you the monthly premium, deductible, copay, and estimated annual out-of-pocket cost side by side. Print or save this comparison before you enroll so you have proof of what you were promised.

When and how to change your plan

Open enrollment for Medicare runs from October 15 to December 7 each year. Changes take effect January 1. You can enroll in a new plan, switch from Original Medicare to Advantage, or switch from Advantage back to Original Medicare during this window. After December 7, you are locked into your plan for the rest of the year unless you have a may have access to life event.

may have access to life events include turning 65, losing employer coverage, moving to a new state or zip code, getting married or divorced, or having a significant change in income. If any of these happen, you have 60 days from the event to change plans. Report the event to Medicare by calling 1-800-MEDICARE or through your online Medicare account. Do not wait — if you miss the 60-day window, you may be stuck in your current plan until the next open enrollment.

If you are unhappy with your plan during the year, you can switch to Original Medicare during the Medicare Advantage disenrollment period, which runs January 1 to February 14 each year. You cannot switch from one Advantage plan to another Advantage plan outside of open enrollment, and you cannot switch from Original Medicare to Advantage outside of open enrollment.

Common mistakes to avoid

The biggest mistake is choosing a plan based on monthly premium without checking whether your doctors are in-network. A plan that costs $50 less per month but forces you to change doctors will cost you thousands in out-of-pocket care. The second mistake is not checking the formulary for your prescription drugs. A plan that looks cheap might not cover your medications at all, or might require prior authorization that delays your refills.

A third mistake is waiting until after December 7 to think about your plan. If you realize in January that your plan does not cover your doctor, you are stuck until October. Start comparing plans in September so you have time to call your doctors and pharmacies and confirm coverage before you enroll.

Do not assume that a plan with a $0 monthly premium is always cheaper. The copays and deductibles might be high enough that you pay more overall. Do not assume that the plan you chose last year is still the best choice this year — formularies change, networks change, and premiums change. Review your plan every October, even if you think you are happy with it.

Frequently Asked Questions

Can I switch Medicare plans if I realize I made a mistake?

If you switch during open enrollment (October 15 to December 7) and then change your mind, you have until December 31 to switch again. If you switch outside of open enrollment because of a may have access to life event, you cannot switch back unless another may have access to event happens. If you are on Medicare Advantage and want to switch to Original Medicare, you can do so January 1 to February 14 each year.

What happens if I do not choose a plan by December 7?

If you are new to Medicare and do not enroll in Part B or Part D by your important date, you pay a permanent surcharge when you finally enroll — roughly 10 percent of the Part B premium for each month you were uninsured, for the rest of your life. If you already have Medicare and do not change your plan during open enrollment, you stay in your current plan.

Should I choose Original Medicare or Medicare Advantage?

Choose Original Medicare if you want to see any doctor anywhere in the country, if you see many specialists, or if you travel frequently. Choose Medicare Advantage if you want lower monthly costs, predictable copays, and you are willing to use in-network doctors in your area. If cost is your main concern, calculate the total out-of-pocket cost for both options using your actual doctors and medications — the answer will be different for everyone.

Can I have both Medicare Advantage and Medigap at the same time?

No. Medigap is designed to work with Original Medicare. If you have Medicare Advantage, you cannot buy Medigap. Some Advantage plans include benefits similar to Medigap, like dental or vision, but they are not the same thing. If you switch from Advantage to Original Medicare, you can buy Medigap, but insurers can charge you more if you wait — the best rates are available if you enroll in Medigap within 63 days of turning 65 or losing other coverage.

How do I know if my pharmacy is in-network?

Use the plan finder on Medicare.gov to search for your pharmacy by name and location. If your regular pharmacy is out-of-network, ask whether the plan will cover your prescriptions if you fill them there, or whether you must switch to an in-network pharmacy. Some plans cover out-of-network pharmacies at a higher copay. If you live in a rural area with few pharmacies, confirm that at least one pharmacy near you is in-network before you enroll.