The 2021 Medicare Star Ratings were released October 8, 2020 with an unprecedented COVID-19 pandemic backdrop. Earlier this year, CMS issued an Interim Final Rule (IFR) that modified and reduced 2020 data collection and submission requirements impacting 2021 Star Ratings, including: HEDIS data, 2020 CAHPS, and postponing the scheduled 2020 Health Outcomes Survey (HOS). The shift aimed to alleviate a health plan’s paperwork burden and redirect resources to reinforce a focus on patient care and well-being. The new guidance, however, did not eliminate 2021 data submission requirements measuring a health plan’s performance throughout 2020 during the pandemic.

Graphic Description

This graph represents a timeline of modifications to data collection and submission regarding Star Ratings for 2020 and 2021.

Key takeaways for 2020 include:
The removal of CAHPS in April 2020. The 2021 Star Ratings include the use of 2020 Stars, and is comprised of 2018 HEDIS & 2019 CAHPS data.

Key takeaways for 2021 include:
2022 Star Ratings will be comprised of 2020 HEDIS, 2020 HOS, and 2021 CAHPS data.

With these changes, approximately 50-55% of 2021 Star Ratings were calculated using 2018 performance data, which was used for the 2020 plan year. Put another way, between 45% and 50% of 2021 ratings are based on 2019 data.

The 2021 Star Ratings reaffirm the significance of patient experiences/complaints and access measures (collectively referred to herein as “patient experience”) where the industry experienced the weight increase from 1.5 to 2. To continue its commitment in this domain CMS announced in the IFC, starting in 2023, further changes increasing the weight of patient experience measures from 2 to 4. The measures include the patient experience of care measures collected through the CAHPS survey, Members Choosing to Leave the Plan, Appeals, Call Center, and Complaints measures. However, the absence of 2020 data submission for HEDIS measures has implications for investments health plans make to drive improvements. Absent reporting new data, HEDIS improvements made during the 2019 performance year are not reflected in Star Ratings affecting future MA payments. This disproportionately impacts low-performing MA plans that made investments to improve their Star Ratings, while most national MA plans have maintained an edge in this regard. Described below, a large number of underperforming plans scored poorly in their patient experience measures, which will compound the adverse impact.


There are various trends evidenced in the 2021 Star Ratings. While there is one more 5 Star plan for 2021 compared to 2020, there are fewer total plans in 2021 that rate 4 Stars or higher compared to 2020 (195 to 210). There are also more 3 Star plans in 2021 compared to 2020 (61 to 55). The number of 2.5 Star plans is the same at 4, and there was one 1 Star plan. This shows a global decrease in Stars at a rate of 21% year over year compared to 17% of plans experiencing increases.

While many of the measures utilized the 2020 rating, some non-HEDIS scores changed despite the carryforward of the 2020 results. The following measures trended down in the 2021 Star Ratings:

Measures Trending Down

Improving or Maintaining Mental Health
Complaints about the Health Plan
Members Choosing to Leave the Plan
Health Plan Quality Improvement
Plan Makes Timely Decisions about Appeals
Reviewing Appeals Decisions
Call Center – Foreign Language Interpreter and TTY Availability
Appeals Auto-Forward
Appeals Upheld
Complaints about the Drug Plan
Members Choosing to Leave the Plan
Drug Plan Quality Improvement
Rating of Drug Plan
Getting Needed Prescription Drugs
MPF Price Accuracy
Medication Adherence for Diabetes Medications
Medication Adherence for Hypertension (RAS antagonist)
Medication Adherence for Cholesterol
MTM Program Completion Rate for CMR
Statin Use in Persons with Diabetes (SUPD)

There are several market trends worth noting that will influence future strategy. Plans that lost at least half a Star did so by losing ground on Part D. Star reductions were a result of Part D losses at a rate of almost three to one compared to Part C losses. Separately, plans that increased at least half a Star did so through a balanced approach with a cause ratio of .84 to 1, reflecting a Part C and D improvements trend in a near 1 to 1 ratio. At a corporate level, five parent companies accounted for 45% of all declining plans. Of note, these five parent companies hold more than 60% of the market share of all MA enrollment nationwide, and accounted for 86% of net enrollment growth between 2015 and 2018.

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Patient Experience

Plans that experienced any downward trending are largely associated with the change in CAHPS weighting. Those plans that underperformed were additionally penalized with the patient experience weight changes. Specifically, of those plans whose ratings fell from 2020 to 2021:

  • 85 plans had an average CAHPS score of 3.3
  • 63 of the 85 plans (5.0M lives) averaged 3.8 or lower
  • Of those plans, 49 (2.72M lives) had average CAHPS scores of 3.5 or lower

The impact of the change in weighting has large implications for the 2021 and future Star Ratings where plans need a laser focus in this domain. For Medicare Advantage, the change from 1.5 to 2 increased the proportion of these measures by about 7% on the overall Star score for the same level of performance. The 2023 change from 2 to 4 will increase the proportion of these measures by 23%. The substantial 1.5 to 4 weight changes between 2020 and 2023 will reflect a 28% increase in weight. In 2023, these measures will account for 46% of all MA plan Stars.

For MA-PD the change from 1.5 to 2 increased the proportion of these measures by about 9% on the overall Star score for the same level of performance. The weight increase from 2 to 4 will increase the proportion of these measures by 22%. Further, the 1.5 to 4 weighting change between 2020 and 2023 reflects a 27% increase in weight. In 2023, these measures will account for 40% of all MA-PD plan Stars.

Prior to these weight changes, member satisfaction was critical to growth. A recent JD Power Study demonstrated how a lack of information and communication impacts member satisfaction, producing inadequate engagement among members and an increased likelihood of health plan members switching plans. The following are some of the key findings of this study:

  • Effective communication drives satisfaction and trust
  • Only 15% of plans deliver on all information and communication performance indicators
  • Digital plays a key role in plan selection with 40% of Medicare Advantage members engaging digitally when searching for information on healthcare coverage
  • Telehealth coverage is critical with 20% of Medicare plan members reporting they are interested in receiving information about telehealth

Member satisfaction directly impacts member retention. Using Star measure C28 (Members Choosing to Leave the Plan) as a proxy for voluntary disenrollment, 2021 Star Ratings exhibit a  member churn  increase for Medicare Advantage plans from 2020 (up 1.2% for the average and 2% for the contract median). This reflects a seven-year high for overall MA voluntary churn with 25% of plans having a churn rate of 19% or higher.

While premiums are the lowest they have been in 14 years (since 2007), plans can no longer compete largely on price with consumer satisfaction and experience being one of the most salient features. This trend will become more pronounced going forward. Staying in touch with, and attuned to, members’ needs and sentiments enables a constant understanding of what is, and is not, effective and accelerates a continued refinement in programs to help increase satisfaction and improve experience. One of the best and most successful ways to execute is for plans to deploy pre-CAHPS surveys during the year and use the results to provide meaningful interventions to dissatisfied members.


Pharmacy and the Part D measures continue to underperform compared to the Part C measures. However, pharmacy plays a critical role in overall Star Ratings. An analysis of CMS’ Star Ratings conducted by AdhereHealth, illustrates that 50% of the aggregate weighting is tied to medication adherence. For example, the C15-Diabetes Care—Blood Sugar Controlled measure is directly linked to and correlated with diabetic medication adherence because this measure cannot improve without the proper medication regimen. A plan scoring well on diabetic medication adherence (D14-SUPD) will  likely  translate into similar performance on the C15 measure. This measure has recently increased in importance with the change in weight from 1 to 3 for the 2021 Star Ratings.

The AdhereHealth analysis shows that 40% of the unique measures in the Part C and D Star Ratings relate in some way to medication behaviors. In addition, 5 of 7 three-weighted measures relate to pharmacy adherence.

The role of pharmacy during COVID-19 is more pronounced with a greater need than ever to message the importance of medication adherence. With the new restrictions, many people are foregoing critical health activities such as going to the doctor or pharmacy. The Harris Poll studied this trend between March and September 2020, asking people, “Would you leave your home to go to the pharmacy?” Over this time frame between 18% and 22% of individuals reported they would not go to the pharmacy. While the survey doesn’t factor in medication home or mail delivery, this finding validates a trend that people will forgo basic healthcare activities during this pandemic.

This trend was also covered in a recent Icario article titled COVID’s Catastrophic Impact on Human Health Ignites Historic Era of Illness, Chronic Disease and Premature Death discussing the drop in accessing healthcare and the individual and societal implications. With this decline, plans will need to proactively message the need to refill medication and deploy personalized communication and information to drive health action.

By engaging the member early on, a plan can glean insights into behavior that manifests in deficient medication fill and refill. For example, early communication and information collection can help target individuals facing social determinants of health (SDoH) issues that impede the ability to go to the pharmacy and fill medication. Lack of food, access to the pharmacy, issues with transportation, financial constraints, and health literacy issues all can affect medication adherence. We know during this period of time the number of individuals facing SDoH has grown exponentially. Implementing a comprehensive SDoH program and addressing the genesis of nonadherence can influence a plan’s Star Rating and member health.

With this in mind, a strategic communication approach on medication adherence can influence overall Star Ratings in a substantial way. Tying Part D to Part C outcome measures helps to amplify and cascade the effects of improved ratings. The 2021 Star Ratings continue to demonstrate how Part D performance is lagging compared to Part C. Plans will need to deploy frictionless and barrierless communication to drive health actions that can influence improvement in Part D and the corresponding Part C measures.

Going Forward

HEDIS data collected in 2020 will manifest in the 2022 Star Ratings. CMS has delayed some of the changes that could create a downward trend in Star Ratings, potentially influencing a plan’s investment in improvements. If plans are able to maintain their current Star Rating for the HEDIS measures, then deploying reinforcements against patient experience measures would be a formidable option to help drive improvements in Star Ratings, quality bonus payments, and rebates as well as improving plan performance in an increasingly concentrated and competitive environment. Icario and Novu have both worked with plans where deploying a targeted communication strategy helps more effectively provide critical information, and it engenders a halo effect driven by nonabrasive and member-centric communication.

In addition, rewards and incentives can be an excellent way to impel responses to pre-CAHPS surveys to take the pulse of the members. While some plans desire to use these to encourage high-risk members to take action, rewards and incentives can provide an overall lift to patient experience scores when applied across the population and not simply with the most chronic care members.

It is critical to deploy a targeted and strategic approach to improve those measures that have the greatest impact on the outcomes and overall rating. The correlation and cascading impact between specific Part D and Part C measures and a focused approach on patient experience measures with increased weightings can amplify the ratings even with a narrow approach. 

Getting ahead and realizing these improvements requires a personalized approach to member communication so the modality matches the literacy level and behavior triggers translate into effective health action.