CMS Star Rating (Hospital Overall Rating)
A 1-to-5 star rating assigned by CMS to each hospital based on 46+ quality measures, covering mortality, safety, readmissions, patient experience, and timely care.
On hospital cost-and-quality pages, CMS Star Rating (Hospital Overall Rating) carries a specific technical meaning that often differs from how the term is used in clinical practice or general medical writing. The definition here is the CMS-file usage. On the LakeQuality value rubric, CMS Star Rating (Hospital Overall Rating) is one of the inputs (directly or indirectly) to the combined cost-and-quality grade. Understanding how the term is computed at CMS — what counts and what does not — is part of reading hospital pages defensibly.
Each hospital page on LakeQuality surfaces the specific CMS Star Rating (Hospital Overall Rating) value for that facility (when CMS reports one), so the general definition here translates into a concrete data point on the per-hospital pages you actually use.
How It Works
The CMS Overall Hospital Quality Star Rating is the most visible hospital quality signal for consumers, prominently displayed on Medicare.gov's Care Compare tool and widely referenced in hospital marketing. CMS introduced the rating in July 2016 and updates it annually, most recently in July 2024 for the 2024 release using 2022-2023 measurement years. The rating aggregates approximately 46 measures across five groups: mortality (22% weight, 7 measures including 30-day mortality for heart attack, heart failure, pneumonia, COPD, stroke, CABG), safety of care (22%, healthcare-associated infections and complications including CLABSI, CAUTI, SSI colon, SSI hysterectomy, MRSA, C. diff), readmissions (22%, 30-day readmissions for HRRP conditions plus hospital-wide readmission), patient experience (22%, HCAHPS domains), and timely and effective care (12%, process measures like emergency department throughput, sepsis bundle compliance, preventive care). CMS uses latent variable modeling and k-means clustering to produce a single composite score and assign stars. In the 2024 release, approximately 13% of hospitals earned 5 stars, 27% earned 4 stars, 35% earned 3 stars, 18% earned 2 stars, and 7% earned 1 star, with 20%+ of hospitals not rated due to insufficient measure volume. Small specialty hospitals like Mayo Clinic Rochester, Cleveland Clinic main campus, and physician-owned surgical hospitals routinely earn 5 stars. Large urban safety-net teaching hospitals like Bellevue, Cook County, and Grady often receive 2-3 stars because they treat the most complex and socially disadvantaged patients. Critics argue the methodology disadvantages hospitals serving low-income populations even after risk adjustment. CMS adopted peer grouping in 2021 that compares hospitals only within their measure-count peer group to partially address this.
Related Terms
- Readmission Rate, The percentage of patients who return to the hospital within 30 days of discharge for the same or related condition, a key quality metric tracked by CMS.
- Mortality Rate (Hospital), The rate of patient deaths within 30 days of hospital admission for specific conditions, risk-adjusted to account for differences in patient severity.
- HCAHPS Survey, The standardized national patient satisfaction survey (Hospital Consumer Assessment of Healthcare Providers and Systems) administered to a random sample of discharged hospital patients, producing publicly reported patient experience scores.
- Leapfrog Hospital Safety Grade, A letter grade (A-F) assigned twice yearly to U.S. hospitals by The Leapfrog Group, a nonprofit founded by large employers, based on 30+ patient safety measures.
- Hospital-Acquired Condition (HAC) Reduction Program, A CMS program that reduces Medicare payments by 1% for the quartile of hospitals with the highest rates of hospital-acquired conditions, including infections and preventable injuries.
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About This Definition
This definition is part of the HospitalCostData Hospital Pricing Glossary, 47 terms explaining hospital costs, quality ratings, and healthcare billing. Written for patients, journalists, researchers, and healthcare professionals.