The number of Medicare plans available to you depends on where you live and which type of coverage you choose
Medicare itself is one program, but it breaks into distinct coverage types, and within each type, private insurance companies offer dozens or hundreds of different plans. The exact number you can choose from varies by state, county, and year. In 2024, for example, the average person on Medicare could choose from roughly 30 to 50 different plans in their area — but this number shifts annually as insurers enter and leave markets, and it differs significantly between rural and urban counties.
The core split is between Original Medicare (run directly by the federal government) and Medicare Advantage (run by private insurers but paid by Medicare). Then there are Medigap plans (supplemental coverage you buy separately) and Medicare Part D (prescription drug coverage). Understanding which category applies to you narrows the field considerably and helps you understand what you are actually comparing.
Key Takeaways
- Original Medicare is one option; Medicare Advantage plans number in the dozens per county and change yearly.
- Medigap plans come in 10 standardized designs (A through N), but the number of insurers offering each design varies by state.
- Medicare Part D prescription drug plans number around 20 to 30 per county on average, though this varies widely.
- Your location, income, and current health coverage determine which plans you can choose from and when you can switch.
- Plan availability and pricing reset every October, so the options you have this year may not be the same next year.
Original Medicare versus Medicare Advantage: the two main paths
Original Medicare is a single program with two parts: Part A (hospital insurance) and Part B (medical insurance). You do not choose between different versions of Original Medicare — you either enroll in it or you do not. However, most people who choose Original Medicare then add a Medigap plan to cover costs that Original Medicare does not pay, and they add a Part D plan for prescription drugs. This layering creates choice, but the foundation is one.
Medicare Advantage, by contrast, is offered by private insurance companies under contract with Medicare. Each company designs its own plan with its own network of doctors, its own copays, and its own rules about which specialists you need referrals to see. In an average county, 15 to 25 Medicare Advantage plans are available, though some rural counties have only two or three, and some urban areas have 40 or more. These plans change every year — some insurers drop out of a county, others enter, and existing plans change their networks and costs.
Medigap plans: 10 standardized options
If you choose Original Medicare, you can buy a Medigap (supplemental insurance) plan to cover the gaps — the deductibles, copays, and coinsurance that Original Medicare leaves you responsible for. Medigap plans are standardized by federal law into 10 designs, labeled A through N. Plan A is the most basic; Plan G and Plan N are among the most comprehensive. The benefits in Plan A offered by one insurer are identical to Plan A offered by another insurer, but the price varies.
How many Medigap plans you can choose from depends on how many insurance companies sell Medigap in your state. Some states have 20 or more insurers offering Medigap; others have fewer than 10. Within your state, you can typically buy any of the 10 designs from any insurer that sells in your state, so your real choice is which design (A through N) and which insurer. Medigap plans do not change their design every year the way Medicare Advantage plans do, but prices and which insurers are active in your state do change.
Medicare Part D prescription drug plans: 20 to 30 per county
Medicare Part D is prescription drug coverage offered by private insurers. The number of Part D plans available in your county typically ranges from 15 to 35, with an average around 25. Like Medicare Advantage, these plans are offered by different companies, have different formularies (lists of covered drugs), and charge different copays and deductibles. The plans available to you change every year during the annual enrollment period.
Part D is separate from both Original Medicare and Medicare Advantage. If you have Original Medicare, you must add Part D separately if you want prescription drug coverage. If you have Medicare Advantage, most plans include prescription drug coverage, though you can sometimes switch to a standalone Part D plan instead. The choice of which Part D plan to use (if any) is independent of your choice of Original Medicare or Medicare Advantage.
How location affects your plan options
Your county of residence is the primary factor that determines which plans are available to you. An urban county in California might have 50 Medicare Advantage plans; a rural county in Montana might have 3. The same variation applies to Part D plans and to which Medigap insurers operate in your state. When you move, your available plans change, even if you move within the same state.
You can check what plans are available in your specific county using Medicare.gov's plan finder tool. You enter your zip code, and the tool shows you every Original Medicare option (which is the same everywhere), every Medicare Advantage plan available in your county, every Part D plan, and every Medigap plan offered by insurers in your state. This is the only way to know your actual choices — national numbers are useful context, but your county determines what you can actually choose.
When plan options change and how to track them
Medicare's annual enrollment period runs from October 15 through December 7 each year. During this window, insurers announce which plans they will offer the following year, which plans they are discontinuing, and what the new costs will be. Plans that existed last year may disappear. New plans may launch. Existing plans may change their networks, copays, or formularies. This means your options are never static.
If you are already enrolled in a plan, you receive a notice in September or early October showing you what is changing for the next year and what your new premium will be. If you do not like the changes, you can switch during the enrollment period. If you do nothing, you stay in your current plan. Outside the annual enrollment period, you can switch plans only if you have a may have access to life event — moving to a new county, losing other health coverage, or becoming newly may be able to access for Medicare.
Special enrollment periods and when you can switch outside October
Most people can only change plans during the annual enrollment period in October and November. However, certain situations trigger a Special Enrollment Period that lets you switch at other times of year. These include moving to a new county, losing employer coverage, becoming newly may be able to access for Medicare, or having your current plan leave the market.
If you move to a different county, you may find that your current plan is no longer available in your new location. In that case, you have 60 days from your move to switch to a plan available in your new county. If your current plan is discontinuing, Medicare notifies you and gives you a window to switch. If you lose other health coverage, you have 60 days to enroll in a Medicare plan. Understanding these windows matters because missing them can lock you into a plan you did not choose or leave you without coverage.
Income-based help narrows your options in some cases
If your income is low enough to may have access to for Extra Help (federal information with Part D costs) or Medicaid (state health coverage), your plan options may be limited. Some Part D plans are designated for people receiving Extra Help, and some are not. If you may have access to for both Medicare and Medicaid, you are a "dual may be able to access" and may be required or strongly encouraged to enroll in a special Medicare Advantage plan designed for dual-may be able to access people in your state.
Your state Medicaid office and your local Area Agency on Aging can tell you whether these restrictions explore to you and which plans you are may be able to access for. This is worth checking before you choose a plan, because it can significantly narrow your options and affect your out-of-pocket costs.
Frequently Asked Questions
Can I switch between Original Medicare and Medicare Advantage whenever I want?
No. You can switch during the annual enrollment period (October 15 to December 7) or if you have a may have access to life event like moving to a new county. Outside these windows, you are locked into your choice for the year. If you switch from Medicare Advantage to Original Medicare, you have a one-time window to buy a Medigap plan without medical underwriting; after that window closes, insurers can deny you or charge more based on your health.
Does every county have the same number of Medicare Advantage plans?
No. Rural counties often have only two or three Medicare Advantage plans available, while urban counties may have 40 or more. The number also changes year to year as insurers enter and leave markets. You can see exactly how many plans are available in your county by entering your zip code into Medicare.gov's plan finder.
If I like my current plan, do I have to do anything during enrollment?
You do not have to switch, but you should review your plan's notice of changes in September or October. Your premium may increase, your copays may change, or your doctor may leave the network. If you are satisfied after reviewing the changes, you can do nothing and stay enrolled. If something has changed that bothers you, the enrollment period is your chance to switch.
Are Medigap plans the same everywhere?
The benefits in each Medigap design (Plan A, Plan B, etc.) are standardized by federal law, so Plan G is the same whether you buy it in New York or California. However, the price varies by state and by insurer, and not all insurers sell all plans in all states. You can only buy plans from insurers that operate in your state.
What if my Medicare Advantage plan is discontinued?
Medicare notifies you by mail if your plan is being discontinued. You then have a window (usually several weeks) to switch to another plan without penalty. If you do not choose a new plan during this window, Medicare will automatically enroll you in another plan in your area, though you can change this choice if you do not like the automatic assignment.