If you’ve ever searched for a nursing home on Medicare’s Care Compare website, you’ve seen the one-to-five-star overall rating displayed prominently at the top of every facility page. That rating is calculated by the Centers for Medicare & Medicaid Services (CMS) and is the most widely cited measure of nursing home quality in the United States.
But most families don’t know what actually goes into it ??? or where it falls short.
How CMS Calculates the Star Rating
The CMS five-star rating is a composite of three separate domain ratings:
1. Health Inspections (weighted most heavily)
This domain is based on the last three years of annual inspections plus any complaint investigations. CMS ranks facilities within each state and assigns stars based on their relative deficiency count and severity. A facility in the bottom 20% of its state gets one star here; the top 10% gets five stars.
Important caveat: state inspection programs vary significantly in rigor. A four-star health inspection rating in one state may represent a very different level of scrutiny than the same rating in another.
2. Staffing
CMS measures two staffing metrics: total nursing hours per resident per day and RN hours per resident per day. These are self-reported by facilities but cross-checked against payroll data (PBJ ??? Payroll-Based Journal) submitted quarterly to CMS.
Staffing levels matter because understaffing is consistently the strongest predictor of adverse events in nursing homes ??? falls, pressure ulcers, medication errors, and infections all increase when there aren’t enough nurses.
3. Quality Measures
This domain uses clinical outcomes data from Minimum Data Set (MDS) assessments ??? standardized health assessments completed for every nursing home resident. It covers things like percentage of residents with pressure ulcers, antipsychotic medication use, falls with major injury, and functional decline.
Where the CMS Rating Falls Short
The CMS star system is a useful starting point, but it has well-documented limitations:
- Gaming is common. Facilities have learned to optimize for the specific metrics CMS measures while other aspects of care may suffer. A 2022 study in Health Affairs found facilities cluster suspiciously at rating cutoff points.
- State-to-state comparisons are unreliable. Because health inspection stars are relative to a state’s peer group, a three-star facility in a high-performing state may actually have a better record than a four-star facility in a low-performing state.
- Complaints aren’t weighted equally. CMS includes complaint surveys in the inspection domain, but the weighting underemphasizes facilities with chronic, low-level complaints versus those with single dramatic events.
- The rating updates slowly. Annual inspections mean a facility can have a serious, ongoing problem and not have it reflected in its rating for months.
What We Do Differently
The Care Safety Signal??? score on Senior Care Report Card pulls from the same CMS data sources but weights the components differently to better reflect actual risk to residents:
- Inspection history (30%) ??? deficiency count and severity over the last 3 survey cycles
- Violation severity and penalties (25%) ??? Immediate Jeopardy citations and civil money penalties carry extra weight
- Staffing levels (25%) ??? RN and total nursing hours per resident day, benchmarked nationally
- Complaint history (20%) ??? substantiated complaints filed by residents and families
The result is a 0???100 score where 70+ is generally good, 50???69 warrants further scrutiny, and below 50 represents a meaningful safety concern based on the public record.
How to Use Safety Scores in Your Search
No score ??? CMS stars or otherwise ??? should be the only factor in choosing a nursing home. Use the score to filter out obvious red flags quickly, then dig into the underlying data for any facility you’re seriously considering. Read the inspection narratives. Look at the trend over time. Visit in person at different times of day.
Search any nursing home on Senior Care Report Card to see its Care Safety Signal??? score, full inspection history, staffing data, and penalty record ??? all updated monthly from CMS.