Onyx Blog
Better HEDIS Performance Starts with Better Data
Most health plans have spent years investing in data infrastructure: new platforms, integrations, and vendor relationships. Yet too much quality data still arrives late, sits in disconnected systems, and requires chasing down records before it can be used.
That gap matters more as performance benchmarks rise and HEDIS reporting becomes increasingly digital. Better performance depends on data that is connected, current, and usable throughout the measurement year.
The 2026 Medicare Advantage Star Ratings told a familiar story. The average rating across contracts came in at 3.66 — barely above 2025’s 3.65, and part of a multi-year plateau following consecutive declines since 2022, according to the CMS 2026 Star Ratings Fact Sheet and Chartis’ 2026 Star Ratings analysis. Only 18 contracts earned 5 Stars, and the share of 4+ Star contracts remained flat at approximately 40%.
For contracts below the 4-Star threshold, the financial impact can be significant — affecting quality bonus payments, rebates, competitiveness, and reinvestment capacity.
What makes this harder is the long tail of Stars. The data CMS uses to calculate your rating may be one to two years old by the time it affects your revenue. What your quality team does today will not show up in your payment rates until next year — or the year after. Plans that lose focus do not feel it immediately. They feel it later, when it is harder to recover.
A half-star drop is not just a bad report card. At scale, it can become a direct hit to revenue, a reduction in competitive advantage, and at organizations where leadership is judged on Stars performance, the kind of outcome that triggers real consequences.
HEDIS measurement should be a data problem by now. Instead, for many plans, it is still a labor problem.
Clinical teams spend significant time every year requesting, reviewing, and abstracting medical records to verify that members received preventive services. Supplemental data from EHRs, labs, and pharmacies arrives late — often too late for care teams to act on it before the measure window closes. Scores get calculated months after the clinical events that should have informed them.
The result is Stars performance that lags behind clinical reality. Gaps that were actually closed do not get counted. Members who needed outreach did not get it in time. Revenue that should have been protected may be at risk.
Digital quality starts with a simple premise: your Stars performance is a downstream output of your data quality.
You cannot improve one without addressing the other.
That means getting three things right: unified member records, continuous computation, and actionable stratification.
Claims, clinical, and pharmacy data need to live in one place, updated continuously. When these sources are siloed, gaps get missed because no single system has the full picture. A member who received a preventive screening from their primary care physician should not have that event invisible to your HEDIS computation engine because the clinical data never made it into the right system.
HEDIS computation that runs once a year is always behind. By the time you know where your gaps are, the window to close many of them has already passed.
And not all gaps are equal. Member prioritization based on gap burden, closure likelihood, and measure weight lets care teams focus their outreach where it actually moves the Stars needle.
A regional payer came to Onyx with a problem that many plans would recognize. Their claims, clinical, and pharmacy data lived in separate systems with no reliable way to bring them together. Reporting was delayed. HEDIS scores were not reflecting what was actually happening in the population.
Onyx built a cloud-native HEDIS computation platform that pulled all three data sources into a unified member record, ran computation continuously, and deployed real-time population health dashboards so care teams could see gaps and act on them throughout the year — not just chase them at year end.
The results: a 20% increase in Medicare Advantage Star Ratings, 30% improvement in HEDIS score accuracy across measures, and a 60% reduction in compliance risk exposure, as shown in the Onyx HEDIS Analytics Platform Case Study.
The scores improved because the data improved.
The care team did not work harder. They worked from better information, earlier.
The contracts that consistently hold 4+ Stars are not doing something operationally heroic every year. They have made a structural choice: to treat quality measurement as a continuous data operation, not an annual reporting exercise.
When that infrastructure is in place, Stars performance reflects what your plan actually delivers.
When it is not, you are always measuring yesterday.
OnyxOS automates HEDIS computation end-to-end — aggregating supplemental data from EHR, HIE, claims, and pharmacy sources, running continuous measure calculation, and surfacing care gaps and Stars trajectory in real time.
Explore Digital Quality on OnyxOS →
Better data is the starting point. The next step is readiness.
Download From FHIR Compliance to Digital HEDIS Readiness for a practical, step-by-step framework to assess clinical data flows, FHIR/HEDIS IG alignment, CQL engine ownership, vendor readiness, governance, financial modeling, and roadmap planning.
Download the Guide
