Hospital Star Ratings Explained
Published: 10 June 2026 · Written by: HospitalGuide Medical Editorial Board
What do hospital star ratings mean and how are they calculated?
Hospital star ratings — most notably the CMS Overall Hospital Quality Star Rating in the USA and CQC inspection ratings in the UK — summarise dozens of clinical performance measures into a single score. They help patients compare facilities, but understanding what the rating measures is essential to interpreting it correctly.
USA: CMS Overall Hospital Quality Star Rating
The Centers for Medicare & Medicaid Services rates eligible hospitals 1–5 stars on Medicare Care Compare. The rating is derived from five measure groups:
- Mortality (22%): Death rates for common conditions vs national average
- Safety of Care (22%): Hospital-acquired infections and complications
- Readmission (22%): Rate of patients readmitted within 30 days
- Patient Experience (22%): HCAHPS survey scores — communication, responsiveness, cleanliness
- Timely & Effective Care (12%): Time to treatment, process measures
UK: CQC Inspection Ratings
The Care Quality Commission rates NHS trusts and independent providers across five domains: Safe, Effective, Caring, Responsive, and Well-led. Overall ratings are: Outstanding, Good, Requires Improvement, or Inadequate. Ratings are assigned following on-site inspections.
How to Use Ratings Wisely
- A 3-star hospital may excel at the specific procedure you need — look at procedure-specific data, not just the overall score.
- Small hospitals may have fewer reportable measures, making comparisons less reliable.
- Ratings lag real-world changes — a recently improved hospital may still carry an older low rating.
Frequently Asked Questions
What percentage of US hospitals are 5-star rated?
Approximately 7% of eligible hospitals receive a 5-star CMS rating in any given year. Around 18% receive 4 stars, 24% receive 3 stars, 17% receive 2 stars, and 4% receive 1 star. The remainder are not rated due to insufficient data.
Does a high star rating guarantee better care for my condition?
Not necessarily. The overall rating averages many conditions. For a specific procedure like hip replacement or cardiac surgery, check specialty-specific volumes and outcome data via the Leapfrog Group or NHS procedure-level statistics.
Where can I find CMS hospital star ratings?
Visit Medicare.gov/care-compare, search for your hospital by name, city, or zip code, and select "Overall rating" from the results. Ratings are updated annually.
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Editorial Transparency: This guide was reviewed by the HospitalGuide Medical Editorial Board against standard hospital policies and applicable patient rights legislation (HIPAA, NHS standards, Privacy Act). Content is updated when material regulatory changes occur.
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Medical Disclaimer: This guide is for informational purposes only and does not constitute medical, legal, or clinical advice. Always contact your healthcare provider or relevant authority directly. In a medical emergency, call 911 (USA/Canada), 999 (UK), 000 (Australia), or 112 (Europe) immediately. Full Medical Disclaimer →