Medicare Advantage Enrollment by County: A Complete 2024 Guide

Table of Contents#

1. What Drives Medicare Advantage Enrollment Differences Across Counties?
2. Step-by-Step Guide to Looking Up Your County’s MA Enrollment Data
3. What High vs. Low MA Enrollment in Your County Means for You
4. Common Misconceptions About County-Level MA Enrollment
5. Tips for Choosing the Best MA Plan in Your County
6. Conclusion
7. References

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1. What Drives Medicare Advantage Enrollment Differences Across Counties?#

Enrollment gaps are almost never random. Four core factors explain most variation between counties:

1.1 Plan Availability and Carrier Competition#

Per 2024 KFF data, the average Medicare beneficiary has access to 43 MA plans. However, this varies significantly by geography: beneficiaries in urban areas have an average of 46 plans to choose from, compared to 30 plans in rural counties adjacent to urban areas, and 22 plans in the most rural counties. Carriers prefer to operate in counties with large senior populations to build larger risk pools, spread costs, and offer more generous supplemental benefits (such as dental, vision, OTC allowances, and fitness memberships). Although plan choices are numerous, local markets are highly concentrated: 47% of all MA enrollees are in plans sponsored by just two firms (UnitedHealthcare and Humana).

1.2 State Medicaid Policies and Federal Preemption#

While Medicare Advantage is a federally regulated program (meaning states generally cannot regulate core plan operations like prior authorization due to federal preemption), state-level policies still indirectly influence local markets:

• Medicaid Expansion: States that expanded Medicaid under the Affordable Care Act (ACA) have higher eligibility rates for low-income seniors. This has spurred insurers to offer more Dual Eligible Special Needs Plans (D-SNPs) to coordinate care, driving higher overall MA enrollment in those states.
• Medigap Protections: In states with strong consumer protections for Medicare Supplement Insurance (Medigap)—such as New York, Connecticut, and Massachusetts, which require year-round guaranteed issue or community rating—beneficiaries can easily switch back to Traditional Medicare + Medigap without health-based premium increases. This makes Traditional Medicare highly attractive and results in lower MA enrollment rates in these areas. In contrast, in the 46 states without these year-round protections, fear of being locked out of Medigap if their health declines encourages beneficiaries to remain in MA plans.

1.3 Local Demographic Trends#

Counties with higher shares of seniors with chronic conditions, low household incomes, or prior experience with managed care (such as HMO/PPO employer plans) have far higher MA enrollment. For example, metropolitan areas in Florida, Ohio, and Pennsylvania have some of the highest MA penetration rates in the country, as large senior populations prioritize low-cost MA plans with extra benefits.

1.4 Carrier Outreach and Marketing#

Carriers invest heavily in advertising in highly populated counties to maximize enrollment. According to KFF data, Medicare Advantage ads accounted for over 85% of all television airings for Medicare plans during the fall open enrollment season, with one analysis showing more than 643,000 ad airings during a single enrollment period (averaging over 9,500 ads per day). This massive volume of marketing significantly drives awareness and enrollment in areas where these ads are concentrated.

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2. Step-by-Step Guide to Looking Up Your County’s MA Enrollment Data#

You can access free, official county-level MA data in 4 simple steps:

1. Use the CMS MA Enrollment Dashboard (link in references) or the KFF County-Level MA Report for simplified, pre-analyzed data.
2. Filter results by your state, then select your county from the dropdown menu.
3. Review key metrics for your area:
   • Total MA enrollees
   • MA penetration rate (share of all local Medicare beneficiaries enrolled in MA)
   • Number of available MA plans
   • Average monthly premium for MA plans in your county
   • Share of plans with 4+ star CMS quality ratings
4. Compare your county’s metrics to state and national averages to contextualize your local plan landscape.

If you prefer not to use online tools, call 1-800-MEDICARE to request your county’s MA enrollment and plan information over the phone.

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3. What High vs. Low MA Enrollment in Your County Means for You#

Enrollment rates are a useful signal of your local plan market’s strengths and weaknesses. Below is a summary comparison of what you can typically expect in high vs. low enrollment counties, followed by detailed pros and cons:

3.1 High MA Enrollment (Over 50% Penetration)#

Pros#

• More plan options to choose from, including specialized SNPs for chronic conditions or dual eligibility.
• Lower average premiums (typically 30% lower than low-enrollment counties).
• More generous extra benefits, including comprehensive dental, transportation, and meal delivery allowances.
• Larger provider networks in HMOs, as carriers compete to include top local doctors and hospitals.

Cons#

• Higher volume of marketing calls and mailings from MA carriers.
• Higher risk of scam marketing targeting local seniors.
• Narrow network HMO plans may dominate, as carriers cut costs to compete on price.
• Prior authorization and utilization management restrictions are highly prevalent, as carriers actively manage care to control costs.

3.2 Low MA Enrollment (Under 30% Penetration)#

Pros#

• Fewer marketing scams targeting local seniors.
• Available plans often have broader PPO networks to attract enrollees.
• Less competition can mean more personalized customer service from carriers.

Cons#

• Fewer plan options, and often no SNPs for people with specialized needs.
• Average premiums are 25% higher than in high-enrollment counties.
• Fewer extra benefits, with most plans only offering basic dental and vision coverage.
• Smaller provider networks, as local doctors and hospitals are less likely to participate in MA networks when traditional Medicare is the dominant choice.

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4. Common Misconceptions About County-Level MA Enrollment#

Misconception 1: Low MA enrollment means MA plans in my county are low-quality#

False. Low enrollment almost always stems from low carrier competition in low-population areas, not poor plan performance. Many low-enrollment counties have only 1 or 2 MA plans with 4+ star ratings.

Misconception 2: High enrollment means all MA plans in my county are good#

False. High enrollment can be driven by heavy marketing spending, not high plan quality. Always cross-reference enrollment rates with CMS star ratings, which measure customer satisfaction and care outcomes.

Misconception 3: I can only enroll in MA plans offered in my county of residence#

Mostly true. You must enroll in a plan based on your permanent, primary residence (defined by your address registered with the Social Security Administration). However, if you split time between locations (like snowbirds), you do not need separate plans. Instead, you can choose a PPO plan with a "visitor" or "traveler" benefit that allows you to receive in-network care in both locations, or a plan with nationwide out-of-network coverage.

Misconception 4: County enrollment rates don’t impact my out-of-pocket costs#

False. Higher enrollment means larger risk pools for carriers, so they can spread medical costs across more people, leading to lower deductibles and copays for enrollees.

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5. Tips for Choosing the Best MA Plan in Your County#

Follow these steps to pick a plan that fits your needs, regardless of your county’s enrollment rate:

1. Prioritize 4+ star plans first: CMS gives these plans bonus funding, so they often have more generous benefits and better customer service.
2. Confirm network coverage: Verify that your preferred doctors, hospitals, and local pharmacies are in the plan’s network for your county.
3. Compare extra benefits: Don’t just look at premiums—if you need comprehensive dental, transportation, or OTC allowances, prioritize plans that include those benefits for no extra cost.
4. Check for specialized plans: If you have a chronic condition (diabetes, heart failure) or qualify for both Medicare and Medicaid, check if your county offers C-SNPs or D-SNPs tailored to your needs.
5. Use free local help: Contact your local State Health Insurance Assistance Program (SHIP) for free, unbiased guidance from counselors who know your county’s MA plan options.

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Conclusion#

County-level Medicare Advantage enrollment data is a powerful tool to understand your local coverage landscape, but it should never be the only factor you use to choose a plan. Always compare plans based on your individual health needs, budget, and provider preferences, and use free official resources to avoid misleading marketing. Whether your county has high or low MA enrollment, there is likely a plan that fits your needs if you take the time to compare your options.

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References#

1. Centers for Medicare & Medicaid Services (CMS). (2024). Medicare Advantage/Part D Contract and Enrollment Data. Retrieved from https://www.cms.gov/medicare/enrollment-information/medicare-advantagepart-d-contract-and-enrollment-data
2. Kaiser Family Foundation (KFF). (2024). Medicare Advantage in 2024: Enrollment Update and Key Trends. Retrieved from https://www.kff.org/medicare/issue-brief/medicare-advantage-in-2024-enrollment-update-and-key-trends/
3. Centers for Medicare & Medicaid Services (CMS). (2024). State Health Insurance Assistance Program (SHIP) Locator. Retrieved from https://www.shiphelp.org/
4. Centers for Medicare & Medicaid Services (CMS). (2024). Medicare Plan Finder. Retrieved from https://www.medicare.gov/plan-compare/