HEDIS Measures and Scores: A Comprehensive Overview
HEDIS is one of the most widely used quality-measurement tools in U.S. healthcare. This guide explains what HEDIS is, how its measures and scores work, and how quality measurement connects to risk adjustment and the RAF score.
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What Is HEDIS?
HEDIS is a tool used by health plans to measure performance on important dimensions of care and service. Because measures are defined precisely and reported consistently, HEDIS allows apples-to-apples comparison between plans. It is maintained by the NCQA and updated annually to reflect evolving clinical evidence and priorities.
HEDIS Measures
HEDIS includes roughly 90 measures organized across domains such as effectiveness of care, access and availability, experience of care, utilization, and health plan descriptive information. Common examples include controlling high blood pressure, diabetes care, cancer screening, and medication adherence. Each measure has strict technical specifications for the eligible population, numerator, and exclusions.
HEDIS Scores
A HEDIS score is the rate at which a plan meets a given measure for its eligible population. Scores roll up into broader ratings such as the NCQA Health Plan Ratings and feed the CMS Medicare Star Ratings, which directly affect plan bonuses and enrollment.
Why HEDIS Scores Matter in Healthcare
HEDIS scores drive quality bonuses, public reporting, accreditation, and member choice. For organizations in value-based care and population health management, HEDIS performance is both a quality scorecard and a revenue lever.
HEDIS vs. Risk Adjustment
HEDIS measures the quality of care delivered; risk adjustment, expressed as the RAF score, measures the predicted cost and complexity of the population. Both depend on accurate documentation, and both reward proactive chronic-disease management. A strong program treats HEDIS gap closure and accurate HCC capture as two outputs of the same well-documented encounter.
| Aspect | HEDIS | RAF (risk adjustment) |
|---|---|---|
| What it measures | Quality of care delivered | Predicted cost and clinical complexity |
| Built from | Measure specs (eligible population, numerator, exclusions) | HCCs mapped from ICD-10 codes |
| Owner | NCQA | CMS (CMS-HCC model) |
| Drives | Star Ratings, quality bonuses, accreditation | Risk-adjusted capitated payment |
| Resets | Annually | Annually |
| Shared dependency | Both rise or fall on the same accurate, specific clinical documentation | |
Examples of HEDIS Measures (and the Documentation They Require)
HEDIS gaps are not closed by activity alone — they are closed by documented, codable evidence in the record. The examples below pair common measures with the documentation that actually satisfies them (specifications change annually; confirm against the current NCQA technical specifications).
| HEDIS measure | Domain | Documentation that closes the gap |
|---|---|---|
| Controlling High Blood Pressure (CBP) | Effectiveness of care | A qualifying BP reading in the measurement year, documented and coded |
| Glycemic Status Assessment for Diabetes (GSD) | Effectiveness of care | HbA1c result documented; diabetes coded to specificity (also feeds the diabetes HCC) |
| Eye Exam for Patients with Diabetes (EED) | Effectiveness of care | Retinal / dilated eye-exam result documented by an eye-care professional |
| Breast and Colorectal Cancer Screening (BCS / COL) | Prevention and screening | Screening date and result in the record within the measure window |
| Medication Adherence (PDC — diabetes, RAS, statins) | Medicare Part D / Stars | Pharmacy fill history showing ≥80% proportion of days covered |
| Plan All-Cause Readmissions (PCR) | Utilization | Accurate admission / discharge coding; risk-adjusted by condition |
The pattern is consistent: the encounter that closes a HEDIS gap is usually the same encounter that should recapture an HCC. Diabetes coded to specificity for GSD also supports the diabetes-with-complications HCC that feeds the RAF score — one well-documented visit, two financial outcomes.
HEDIS, Star Ratings and Plan Revenue
HEDIS is the single largest input to the CMS Medicare Advantage Star Ratings. Stars are not just a quality scorecard — they are a direct revenue lever that sits alongside (not inside) RAF:
- Quality Bonus Payments (QBP) — MA contracts at 4.0+ Stars earn a percentage add-on to their benchmark, materially raising per-member revenue.
- Higher rebates — higher Stars increase the rebate percentage a plan can reinvest in supplemental benefits, improving competitiveness.
- Enrollment and retention — Star Ratings are shown publicly at shopping time, and a 5-Star plan can enroll members year-round.
This is why HEDIS and risk adjustment are parallel revenue engines from the same documentation: the RAF score sets the base risk-adjusted payment, while Star Ratings (driven heavily by HEDIS) set the bonus and rebate on top. Mismanaging either leaves money on the table even when care quality is strong — the operational case for unifying gap closure with HCC recapture.
Conclusion
HEDIS is the backbone of quality measurement for U.S. health plans. Pairing strong HEDIS performance with accurate risk adjustment gives organizations both the quality and the funding to manage complex populations well.
Where HEDIS and RAF Actually Intersect (Operations View)
A common misconception is that HEDIS measures change RAF scores. They do not. The real intersection is operational: a single well-documented chronic-care encounter can simultaneously close a HEDIS gap and recapture an HCC that feeds the RAF score. Programs that run quality and risk adjustment in separate silos pay for the same patient outreach twice and still miss HCC recapture.
| One encounter | HEDIS outcome | RAF / HCC outcome |
|---|---|---|
| Diabetic annual visit + HbA1c + retinal exam | Closes diabetes-care gaps | Recaptures diabetes-with-complications HCC |
| CKD stage documented and treated | Supports related quality measures | Captures the CKD HCC |
| Medication adherence review | Adherence measures | Reinforces chronic-condition recapture |
See how documentation drives both quality and risk
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Open the RAF Score CalculatorFrequently Asked Questions
HEDIS is a standardized set of performance measures developed by the NCQA that health plans use to measure and report quality of care and service.
According to NCQA, more than 90% of U.S. health plans use HEDIS; it is also used by employers, regulators, and CMS via Star Ratings.
HEDIS includes roughly 90 measures across multiple domains of care, updated annually by the NCQA.
HEDIS measures the quality of care delivered; the RAF score measures the predicted cost and complexity of the population.
Common HEDIS measures include Controlling High Blood Pressure, glycemic status for diabetes, breast and colorectal cancer screening, eye exam for diabetes, and medication adherence (proportion of days covered).
HEDIS is the largest input to the CMS Medicare Advantage Star Ratings; higher Stars (4.0+) earn quality bonus payments and higher rebates, increasing plan revenue and enrollment.
This page is educational and does not constitute coding, billing, legal, or clinical advice. Standards, quality measures, and CMS rules change over time; always confirm against current official guidance and your organization's compliance team. CPT® is a registered trademark of the American Medical Association; HEDIS® is a registered trademark of the National Committee for Quality Assurance (NCQA). This page is independent and is not affiliated with, endorsed by, or sponsored by CMS, the AMA, or NCQA.