Medicare Star Ratings: The Math Behind Your Plan's Marketing

Here's what Medicare Advantage plans don't advertise: only 37% of MA plans earned 4 stars or higher in 2024, while 23% scored below 3 stars — meaning nearly 1 in 4 plans are performing poorly enough that CMS considers them substandard. Yet these same low-rated plans are actively marketing to seniors with glossy mailers promising "extra benefits" (which are meaningless if your plan can't manage basic medical care or customer service).

Star ratings matter because they determine real money: 5-star plans get bonus payments from CMS worth up to $2.4 billion annually, plus the ability to enroll new members year-round through Special Enrollment Periods. Meanwhile, plans below 3 stars face contract sanctions and potential termination. This creates powerful incentives to game the system — and some carriers have gotten very good at it.

What Star Ratings Actually Measure

CMS evaluates Medicare Advantage and Part D plans across four weighted categories, each designed to capture different aspects of plan performance:

• Customer Service & Care Coordination (30%): Call center responsiveness, provider communication, care transitions
• Health Outcomes & Quality of Care (30%): HEDIS measures like diabetes care, blood pressure control, medication adherence
• Member Complaints & Problems (20%): Grievance rates, appeals, disenrollment patterns, pharmacy complaints
• Drug Plan Performance (20%): Formulary stability, prior authorization rates, pharmacy network adequacy

2024 Star Rating Distribution: The Real Numbers

Here's how Medicare Advantage plans actually performed in the latest ratings, based on CMS data covering 4,127 total MA contracts:

Notice something? While only 3.7% of plans achieve 5-star status, they enroll 2.1 million members — that's an average of 13,816 members per 5-star plan. Compare that to below-3-star plans: 23.1% of all plans but only 1.8 million total members, averaging just 1,885 members per plan. Low-rated plans struggle to attract and retain members (shocking, we know).

Carriers with the Most 5-Star Plans

Based on 2024 data, here are the insurers that have figured out the star rating game:

Kaiser's success isn't accidental — integrated delivery systems (where the insurer owns the hospitals and employs the doctors) have structural advantages in care coordination and outcomes measurement. They can optimize every touchpoint in the patient journey, from appointment scheduling to medication adherence follow-up.

Carriers with the Most Problem Plans

On the flip side, these carriers operate the highest number of plans rated below 3 stars:

WellCare's 59.9% problem rate is particularly concerning given that Centene acquired the company in 2020 specifically to expand its Medicare footprint. Nearly 6 in 10 WellCare plans are underperforming — yet the company continues to market aggressively to seniors in low-income areas.

Case Study: Broward County, Florida Star Rating Reality

Let's look at what star ratings mean for actual seniors in a real market. Broward County, Florida has 47 Medicare Advantage plans available for 2026, serving roughly 284,000 MA enrollees. Here's how they stack up:

Notice the pattern? Higher-rated plans don't necessarily charge higher premiums — both 5-star plans and below-3-star plans offer $0 premium options. This is because star ratings measure quality and service, not benefit generosity. A plan can offer extensive extra benefits while providing terrible customer service (looking at you, WellCare).

The 5-Star Special Enrollment Period: Why It Matters

Here's a benefit most seniors don't know about: if you're enrolled in a 3-star-or-below plan, you can switch to any 5-star plan at any time during the year, not just during Annual Open Enrollment (October 15 - December 7). This Special Enrollment Period exists because CMS recognizes that high-performing plans deserve member growth advantages.

The math works in your favor: if you're stuck in a 2.5-star WellCare plan and discover a 5-star plan in your area, you can switch immediately. No waiting until next October, no qualifying life event required. This SEP applies to both Medicare Advantage and Part D plans, and you can use it once per calendar year.

But there's a catch (there always is): you can only switch FROM a low-rated plan TO a 5-star plan, not the reverse. And if you switch to a 5-star plan, you can't use the 5-star SEP again for 12 months, even if you want to switch to a different 5-star plan.

How Star Ratings Get Gamed (And Why CMS Allows It)

Let's be honest about what we're really measuring. Star ratings aren't pure quality metrics — they're gameable business targets that smart carriers have learned to optimize. Here are the most common manipulation tactics:

HEDIS Cherry-Picking

Healthcare Effectiveness Data and Information Set (HEDIS) measures account for roughly 60% of a plan's star rating score. These include things like "percentage of diabetic members with HbA1c testing" and "blood pressure control rates." Plans game these by:

• Selective marketing: Targeting healthier populations in affluent ZIP codes while avoiding sicker, lower-income areas
• Aggressive member outreach: Calling diabetic members repeatedly to schedule HbA1c tests, offering gift cards for compliance
• Provider pay-for-performance: Paying doctors bonuses specifically for hitting HEDIS targets, not necessarily better patient outcomes

Case in point: UnitedHealthcare's OptumCare subsidiary has teams of nurses whose job is literally to call Medicare Advantage members and remind them to get specific screenings. This improves HEDIS scores and star ratings, but it's unclear if it meaningfully improves health outcomes versus just improving documentation.

Network Manipulation

Plans can boost customer service scores by strategically limiting their provider networks to doctors and facilities they have stronger relationships with. A smaller, more controlled network may score higher on "provider communication" measures, even if it means members have fewer choices or longer wait times for specialists.

The Complaint Rate Game

Member complaint rates factor heavily into star ratings. Some plans have discovered they can improve scores by making the complaint process more difficult — longer phone hold times, complex web forms, requiring multiple calls to resolve issues. Frustrated members often give up rather than file official complaints, artificially lowering the plan's complaint rate.

Why Star Ratings Still Matter (Despite the Gaming)

Even with all the manipulation, star ratings provide valuable signal about plan performance. Here's what the data shows when you look beyond the gaming:

Real Correlation with Member Satisfaction

Plans with higher star ratings consistently show better member retention rates. The 2024 data reveals that 5-star plans have an average annual disenrollment rate of 8.2%, compared to 23.7% for plans below 3 stars. Members vote with their feet, and they're staying with higher-rated plans.

Financial Stability Indicator

Low star ratings often correlate with financial problems. Of the 47 Medicare Advantage contracts terminated by CMS since 2020, 83% had star ratings below 3 stars in their final year. Poor performance and financial instability tend to go hand-in-hand in the insurance business.

Provider Network Quality

Despite network manipulation tactics, higher-rated plans generally maintain more stable provider relationships. CMS measures "provider turnover" as part of the access and availability category, and 5-star plans average 12% annual provider turnover versus 28% for below-3-star plans.

How to Use Star Ratings in Your Plan Selection

Given all the gaming and manipulation, how should you actually use star ratings when choosing a Medicare plan? Here's our data-driven approach:

The 3.5-Star Sweet Spot

Don't assume 5-star plans are always your best option. Many 3.5 and 4-star plans offer better value propositions — similar quality with lower out-of-pocket costs or more generous benefits. The key is understanding what drives a plan's rating:

• Plans rated 4+ stars for customer service but 3 stars overall may have benefit limitations but excellent member support
• Plans with 5-star HEDIS scores but 3.5 stars overall might excel at preventive care but struggle with complex care coordination
• Plans with high complaint scores but lower overall ratings often have great provider networks but poor pharmacy management

Red Flags: When Star Ratings Matter Most

Pay close attention to star ratings in these situations:

• Chronic condition management: If you have diabetes, heart disease, or other chronic conditions, avoid plans below 3.5 stars on health outcomes measures
• Frequent pharmacy use: Plans below 3 stars on drug plan performance often have restrictive formularies and high prior authorization rates
• Complex medical needs: If you require frequent specialist care or have multiple conditions, prioritize plans with 4+ star ratings on care coordination

What Star Ratings Don't Tell You

Star ratings measure plan performance, not benefit value. A 5-star plan with a $500 prescription drug deductible might be worse for your situation than a 3.5-star plan with $0 deductible, depending on your medication needs. Always compare:

• Total estimated annual costs (premiums + deductibles + copays)
• Provider network inclusion for your current doctors
• Prescription drug coverage for your specific medications
• Extra benefits that matter to you (dental, vision, transportation)

The 2026 Star Rating Changes

CMS has announced significant methodology updates for 2026 star ratings that will affect plan scores starting in 2027 measurements:

• Health equity adjustments: Plans serving higher percentages of dual-eligible and disabled members will receive scoring adjustments to account for socioeconomic challenges
• Telehealth integration: New measures for telehealth access and quality, weighted at 5% of total score
• Pharmacy network adequacy: Stricter requirements for pharmacy access, particularly in rural areas
• Mental health parity: Enhanced measurement of mental health and substance abuse treatment access

These changes are designed to reduce gaming opportunities, but expect carriers to adapt their strategies accordingly. The fundamental challenge remains: any standardized quality measure can be optimized for the test rather than genuine improvement.

Bottom Line

Star ratings are an imperfect but useful tool for evaluating Medicare Advantage plans. Here's how to use them effectively:

Do use star ratings as a quality filter — avoid plans consistently rated below 3 stars unless you have compelling reasons (like significantly lower costs or better provider network for your specific needs). Do take advantage of the 5-star Special Enrollment Period if you're stuck in a low-rated plan. Do pay attention to category-specific ratings that matter for your health situation.

Don't assume 5-star plans are automatically your best choice — they often cost more and may not offer the specific benefits you need. Don't ignore all other factors in favor of star ratings — a 3.5-star plan that covers your doctors and medications is better than a 5-star plan that doesn't. Don't expect star ratings to capture everything about plan performance — they measure what's easily quantifiable, not necessarily what matters most to your health.

The real value of star ratings isn't in finding the "perfect" plan — it's in avoiding the genuinely problematic ones. With 23% of Medicare Advantage plans rated below 3 stars, there are plenty of substandard options to steer clear of. Use star ratings as a floor, not a ceiling, for your plan selection process.