If you remember one thing: the overall five-star rating is a roll-up, not a measurement. Two facilities with the same three stars can be very different places.
The Centers for Medicare & Medicaid Services (CMS) publishes a star rating for nearly every certified nursing home in the country. CMS explains the official rating system on its Five-Star Quality Rating System page. It’s the most visible number in the entire system — and the most misread. The overall score combines three separate domains, each collected in a completely different way.
The three domains behind the star
Health inspections carry the most weight. Staffing and quality measures adjust the result up or down. Here’s how they differ — and how much to trust each.
| Domain | What it measures | Source | Trust |
|---|---|---|---|
| Health inspection | On-site survey findings & complaints | State inspectors | High |
| Staffing | Nurse hours per resident per day | Payroll (PBJ) | High |
| Quality measures | 15 clinical outcomes | Facility-reported | Medium |
1. Health inspections — the backbone
This domain reflects what trained state inspectors found on-site over three recent survey cycles, plus complaint investigations. It’s the hardest to game and the most heavily weighted. When the overall star and the health-inspection star disagree, trust the inspection star more.
2. Staffing — payroll-verified hours
Since 2018, staffing is drawn from payroll data (the Payroll-Based Journal), not self-reported estimates. Registered-nurse hours per resident per day is the single figure most consistently linked to better outcomes. A facility can post a decent overall star while running thin on RN coverage — so look at the raw hours, not just the staffing star.
Below roughly 0.5 RN hours per resident per day deserves a hard question on any tour — regardless of the overall star.
3. Quality measures — read with care
The third domain blends 15 clinical outcomes such as falls, pressure ulcers, and re-hospitalizations. Crucially, much of this data is reported by the facility itself. It’s useful, but it’s the domain most worth cross-checking against the inspection record and staffing hours.
Putting it together
Start with the overall star to filter. Then split it apart: weight the health-inspection star most, confirm staffing in raw hours, and treat quality measures as a tiebreaker rather than a verdict. Finally, check the enforcement record and the 18-month trend — a falling 4-star can be a worse bet than a stable 3-star.
Try it on a real facility
See the three domains broken out on a live profile.