Dialysis Center Star Ratings Explained: What 1 to 5 Stars Really Means

How CMS calculates the five-star rating for dialysis facilities, which measures go into it, why most centers get 3 stars, and what to look at beyond the stars.

Updated 2026-09-29. Sources: CMS, Medicare and federal regulations, linked inline.

Every Medicare-certified dialysis center that treats enough patients gets a rating from 1 to 5 stars on Medicare’s Care Compare website. The stars are a handy summary, but they are easy to misread. Here is what they measure and how to use them.

What goes into the rating

CMS builds the star rating from outcome and care-process measures it already collects from every center, such as:

• Survival: the standardized mortality ratio, comparing deaths at the center to what would be expected for its patients.
• Hospital admissions and readmissions: how often patients end up in the hospital, and how often they go back within 30 days of leaving.
• Blood transfusions: a signal of how well anemia is managed.
• Vascular access: the share of patients dialyzing through a fistula, and the share stuck with a catheter for 90 days or longer.
• Dialysis adequacy (Kt/V): whether patients get enough dialysis to clear waste from the blood.

The death, hospitalization, readmission and transfusion measures are risk-adjusted: CMS accounts for age, diabetes, other illnesses and how long patients have been on dialysis, so a center that treats sicker patients is not automatically penalized.

Why most centers get 3 stars

The stars are graded on a curve. Roughly one in ten centers gets 1 star, about a fifth get 2, the largest group gets 3, a bit under a fifth get 4 and fewer than one in ten gets 5. So:

• 3 stars means average, not mediocre.
• 4 or 5 stars puts a center in roughly the top quarter.
• 1 star is a real warning sign worth asking about.

Because the curve is relative, a center can drop a star without getting worse, simply because other centers improved.

Why some centers have no rating

A center shows “Not rated” when it is new or has too few patients for reliable measures. Home-only programs and pediatric units often fall in this group. No rating is not the same as a bad rating.

What the stars leave out

• The patient experience. The star rating does not include the ICH-CAHPS patient survey, which CMS reports separately. We show both on every center page.
• Other published measures such as ER visits and transplant waitlisting. CMS reports them on Care Compare but they do not feed the stars.
• Your practical needs: shift times, home dialysis training, distance and parking.

That is why this site adds a 0–100 Scorecard score that combines up to 21 measures, including the survey and transplant waitlisting, and ranks each center against every other center in the country. Two 3-star centers can be far apart on the score.

Reading a center page

For each measure you will see the center’s number, its state average and the national average, plus a “better / about the same / worse” flag. Under many measures we also show CMS’s own verdict (“Better than expected”, “As expected”, “Worse than expected”). CMS’s verdict accounts for statistical uncertainty: a small center can have a high death rate on paper that is still “as expected” because a handful of patients can swing the number. When the CMS verdict says “Worse than expected”, take it seriously.

A good way to use the ratings

1. Use stars and the Scorecard score to build a shortlist.
2. Look for any measure where CMS says the center is worse than expected, especially deaths, hospital admissions or infections.
3. Ask the center about it on your tour. A good center will know its numbers and what it is doing about them.

Sources: Medicare Care Compare: Dialysis facility star ratings, CMS Dialysis Facility Care Compare technical notes, ESRD Quality Incentive Program.