Medicare Star Ratings are key to health plan success. Star Ratings measure quality—and plans with at least 4 Stars receive 5% quality bonus payments, which can help make them more competitive in the marketplace.
Roughly 1 % of Medicare Advantage Prescription Drug contracts received an overall 5-Star Rating for 2025, with about 40% earning at least 4 Stars, according to CMS (Centers for Medicare & Medicaid Services). That’s down significantly from 68% of plans earning at least 4 Stars in 2022.
As Modern Healthcare reports, recent CMS changes have made it more challenging for Medicare Advantage insurers to receive top scores—making it more important than ever to proactively manage performance for measures, like adherence, that are triple weighted in a plan’s overall Star Ratings score.
Considerations to Successfully Manage Medicare Star Ratings
It’s important to note that overall ratings for 2025 stem from 2023 data. And since 2025 Stars impact 2026 quality bonus payments, how a plan performs today greatly affects its future.
For 2025, CMS reports that thresholds—or cut points—for many measures increased from 2024 ratings, noting several factors including a more compressed distribution of scores. These increased cut points elevate standards for high Star Ratings.
Upcoming changes could also further impact future Star Ratings, like the introduction of the health equity index, which is planned to take effect in 2027 to incentivize high-quality care for the most at-risk members.
So, how can plans better support member health and improve future Star Ratings? Medication adherence plays a key role in a plan’s overall Star Rating and is critical to managing chronic conditions. However, it can be difficult for plans to know how to efficiently evaluate and address adherence and related risks, especially among broad member populations.
Looking at Adherence’s Role in Medicare Star Ratings
CMS uses Proportion of Days Covered (PDC) to measure adherence, as defined by PQA (Pharmacy Quality Alliance). CMS considers a health plan’s population adherent if members have access to their medication at least 80% of days covered based on prescription insurance claims, which indicate the medication fill date and days’ supply.
In determining a plan’s overall Star Rating, three adherence measures are triple-weighted: diabetes, hypertension (RAS antagonists) and cholesterol (statins) medications.
From 2024 to 2025, the average Star Rating for each of these three adherence measures hovered just over 3, with two of them decreasing year over year.
- Diabetes medications decreased from 3.3 to 3.2
- Hypertension medication decreased from 3.4 to 3.3
- Cholesterol increased from 3.2 to 3.3
As these ratings indicate, there is significant room for improvement here. By identifying ways to proactively manage adherence across member populations, plans can improve medication management and ultimately, Star Ratings. This level of evaluation requires specialized clinical knowledge to inform insights.
A Proactive Approach to Managing Adherence
Proactive medication management involves identifying and mitigating risks for non-adherence to make the biggest impact on overall Star Ratings.
To identify risk early, comprehensive pharmacy care leverages robust data and clinical insights to evaluate diverse populations and determine what members are trending toward non-adherence for the triple-weighted measures.
Once these members are identified, high-touch care provides several layers of adherence support, including medication synchronization, patient engagement, medication and refill reminders, home delivery, and adherence packaging. This holistic approach helps plans efficiently and seamlessly address adherence across broad member populations.
Demonstrating Results for Optimized Medicare Star Ratings
This type of comprehensive pharmacy model has been proven to positively impact adherence for the triple-weighted measures. A RAND study published in JMCP shows statistically significant increases in adherence to statins (8.4%) and antihypertensive drugs (4.9%) were associated with one year of participation in the model.
In addition, based on average patient PDC scores, this model achieved 94% adherence rates for diabetes, hypertension and cholesterol medications respectively in 2024. The 94% ratings are considered 5-Star and are significantly higher than the 2024 averages for diabetes (3.2 Stars), hypertension (3.3 Stars) and cholesterol (3.3 Stars) medications.
With a more proactive and comprehensive approach to pharmacy care, plans can increase adherence, proactively prevent medication-related risks, and optimize Star Ratings. This level of pharmacy care supports member health and promotes plan success now and in the future.
