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Understanding the 2021 CMS Star Ratings for Medicare Advantage Plans

by Kris Volrath, Vice President, Platform Design & Operations, on November 13, 2020
Kris Volrath, Vice President, Platform Design & Operations

Lessons learned from the 2021 CMS Star Ratings to prepare us for the lasting effects of COVID-19 on quality improvement initiatives.

An Unprecedented Year

What a difference a year makes! This time last year, Medicare Advantage (MA) plans were reflecting on their 2020 Star Ratings performance as competition stiffened among plans with 4 or more stars. The MA market was growing rapidly, as baby boomers aged into Medicare and increasingly selected MA plans over traditional Medicare offerings. MA plans fine-tuned their quality measurement, reporting and improvement strategies and kicked off the 2020 year strong.

And then COVID-19 hit the world. As providers, health plans and patients alike struggled to figure out immediate needs – such as how to deliver care to those patients who need it the most without putting them or their providers at risk – many ancillary activities, including quality initiatives, were placed on hold.

As a result, in the United States 2021 Star Ratings were calculated a bit differently, and MA plans were informed 2021 Star Ratings measures calculated based on HEDIS and CAHPS would be replaced with values from 2020 Star Ratings (care delivered in 2018). A review of the 2021 Star Rating results shows 2021 Star Ratings decreased nearly 3% from 4.15 to 4.05 compared to 2020 Star Ratings1. Out of the 400 MA plans that received an Overall Star Rating, 22% dropped a half star or more.

So, if 2021 CMS Star Ratings for MA plans were partially based on the previous year’s data, why are they still so important and what accounts for the shift in this year’s Star Ratings over 2020 Star Ratings?

Why are CMS Star Ratings Important?

From a beneficiary, payment and compliance standpoint, the importance of CMS Star Ratings performance continues to increase. Moreover, highly rated plans are awarded Quality Bonus Payments (QBP) and higher rebates that allow them to provide additional supplemental benefits and lower premiums. Meanwhile, plans failing to perform are penalized or risk contract termination for consistently low ratings. Achieving higher CMS Star Ratings is not a “nice to have” – it’s a necessity. Insights into Star Ratings, including overall plan performance, measure-level performance, Star Rating distribution trends, measure weights and measure cut-point movement impact provide a better understanding of the 2021 CMS Star Ratings and your comparative performance to inform your future quality improvement strategies.

2021 CMS Star Ratings Performance Overview

With the adjustments to the 2021 Star Ratings calculations, measure rates from 2020 Star Ratings were used for half of the measures, accounting for approximately 38% of the measure weights. Some health plans may not have expected an Overall Star Rating change from the previous year as a result; however, of the 400 rated plans, 83 dropped a half star, 2 plans dropped a full star, 63 plans increased by a half star, and 2 plans increased a full star. While Part C plan performance dropped minimally, Part D plans realized a decline of 6% from 4.34 to 4.07 stars.

MA-PD Star Ratings Performance (2017 – 2021): Averages are enrollment weighted with enrollment data from December of the measurement year (i.e,: Dec 2019 enrollment for 2019 Ratings)


The declined performance of 13 measures calculated based on actual results from 2019 dates of service (DOS), rather than the prior year results (2018 DOS), contributed heavily to the overall national average decline – in some cases by more than 5% – with the measure weights for 6 of the 13 measures being three-weighted.

  • Status Use in Persons with Diabetes
  • Medication Adherence for Diabetes
  • Medication Adherence for Cholesterol
  • Medication Adherence Hypertension
  • Improving or Maintaining Mental Health
  • Improving or Maintaining Physical Health

The drop in the national Overall Star Rating average means  fewer members are enrolled in high-performing plans with 4 or more Stars, fewer QBPs were given, and there is increased pressure on MA plans to provide the same or improved quality of care, while also covering supplemental benefits – such  as telehealth, transportation and meals – that contribute to better health outcomes. But, with predictive analytics, MA plans can forecast measure trends and the impact to their Overall Star Rating to focus on member-measure targeting to drive improvement.

CMS Star Rating Distribution

Turning to the CMS Star Ratings trends for MA plans, the percentage of contracts earning 4 stars or more decreased from 52% for 2020 CMS Star Ratings to 49% for 2021 CMS Star Ratings. The percentage of MA enrollees in plans with 4 or more stars also decreased from 79% last year to 74% this year2.

Effects of Cut-Point Movement on CMS Star Ratings

Within the measure set that was not adjusted as a result of the current public health emergency, several Star Rating measures saw significant cut-point movement, which caused 156 MA plans to receive lower Star Ratings. Looking at 5-Star cut-points for these measures, we see that 23% tightened, making it more difficult for MA plans to reach 5 Stars, and 16% loosened, making it easier to reach 5 Stars. Similarly, looking at 4-Star cut-points, 25% tightened and 14% loosened.

Since CMS Star Ratings for MA plans are relative scores, a plan’s Star Rating is indicative of how a plan has performed compared to other plans. Having comparative data beyond that of your health plan or last year’s CMS cut-points is critical to more accurately forecasting cut-points and plan performance. Combined with intervention targeting, MA plans can better predict  performance and target members for intervention to improve on the most impactful measures, improving health outcomes and ultimately raising their Overall Star Rating.

Looking Ahead

Innovative tools and technology can help MA plans and providers deliver quality care and improve quality measurement and reporting amid the COVID-19 public health emergency. The expansion of telehealth services and utilization of virtual health platforms are driving quality care delivery for millions of people from the safety of their own home.

To reduce the burden and safety concerns of medical record retrieval and review, clinical data extraction technologies automate access to provider sites and accelerate retrieval of medical records. Employees don’t have to manually retrieve records, further ensuring the safety of our healthcare workers.

For a deeper dive into the 2021 CMS Star Ratings release, check out this on-demand webinar.

Do you know how recently proposed changes outlined in the CMS 2022 Advance Notice will impact your organization? Join us 12/2/2020, at 1 p.m. ET, as industry experts explain how CMS’ proposed payment and risk adjustment policies updates will impact MA plans.

1 Inovalon calculations do not account for CMS’ adjustment for new measures.

2 Averages are enrollment weighted with enrollment data from December of the measurement year (IE: Dec 2019 enrollment for 2019 Ratings).

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