About the data

Every quality figure on this site is a published federal measurement, not our opinion and not a user review. This page explains exactly what each number means, how old it is, and where it falls short.

Coverage

We list 8,204 hospitals across all 50 states. Of those, 4,438 have a published emergency department wait time, 3,516 have a CMS overall star rating, and 4,174 report how many patients left before being seen. The CMS data on this site was published July 22, 2026.

Not every hospital reports every measure. A hospital with no figure is not a hospital performing badly — it usually means too few cases to report, or no emergency department at all. We say so on the page rather than leaving a blank.

Emergency department wait time

This is CMS measure OP_18b: the median time patients spent in the emergency department before leaving, for patients who were treated and discharged rather than admitted.

Three things worth understanding about it:

• It is a median across a full year, not a live queue. A hospital showing three hours will still have quiet Tuesday mornings and six-hour Saturday nights.
• It covers discharged patients only. Patients admitted to the hospital from the emergency department are measured separately, and their waits are typically longer.
• Longer is not automatically worse. Busy trauma centres treat sicker, more complex patients. Compare a hospital to others of similar size and role, which is why we show the state average alongside it.

Left before being seen

The percentage of emergency department patients who left without being evaluated by a clinician. It is a useful companion to the wait time: a moderate wait with a high walkout rate often says more about the experience than either number alone.

Overall star rating

CMS's one-to-five star summary, combining dozens of measures across mortality, safety of care, readmission, patient experience, and timely and effective care.

It is a blunt instrument by design. A hospital must report enough measures to receive one at all, which is why many smaller and specialty hospitals have no star rating here. Two hospitals with the same number of stars can differ substantially on the measure you personally care about. Treat it as a starting point, not a verdict.

Emergency department volume

CMS groups emergency departments into low, medium, high and very high annual volume bands. Volume is context: it tells you whether a wait time reflects a small rural department or a major urban one.

Where it comes from

• Hospital General Information — identity, address, ownership, hospital type, emergency services, star rating
• Timely and Effective Care – Hospital — emergency department timing measures including OP_18b
• CMS Provider Data Catalog — the full catalogue

Both datasets are United States federal government public domain data, refreshed by CMS on a quarterly cycle. We re-import after each release and record what changed, so a figure on this site can always be traced to a specific publication.

How hospitals are matched

Each hospital is keyed to its CMS Certification Number (CCN), the six-character identifier Medicare uses. When a hospital converts to Critical Access or Rural Emergency status it is issued a new CCN; we follow the change and keep the page, rather than creating a duplicate.

What this site is not

• Not affiliated with CMS or with any hospital listed here.
• Not live operational data. Nothing here reflects how busy an emergency department is right now.
• Not medical advice. If you are having a medical emergency, call 911 or go to the nearest emergency department. Do not use a wait time on this page to decide where to go in an emergency.

Corrections

If a figure here is wrong, it is either wrong in the federal source or we have mismatched a record. Both are worth knowing about — tell us which hospital and what is wrong, and we will trace it back to the source release.