88 of the 259 California hospitals that CMS places in an ED volume group (34%) are in its very high volume group, against 703 of 3826 hospitals nationally (18%), by Kent Applied's count of CMS's 2024 ED volume groups.
34%
of California hospitals with an ED volume group are in CMS's very high volume group, by 2024 ED volume
88 of the 259 California hospitals that CMS places in an ED volume group (34%) are in its very high volume group, against 703 of 3826 hospitals nationally (18%), by Kent Applied's count of CMS's 2024 ED volume groups.
CMS sorts hospitals into four groups by 2024 ED volume (its EDV measure). In California and nationally, the bigger the ED group, the longer CMS's median time for patients sent home, except that nationally the high and very high volume groups are about even.
Source: CMS Provider Data Catalog, Timely and Effective Care - Hospital (July 2026 release) (opens in a new tab), California rows, measures OP_18a to OP_18d (October 1, 2024 to September 30, 2025), OP_22 and EDV (2024). Verified October 2026.
Related charts
- From research
By ED size, California's times are near the national ones, except at the smallest EDs
CMS Provider Data Catalog, Timely and Effective Care - State (July 2026 release); CMS Provider Data Catalog, Timely and Effective Care - National (July 2026 release); CMS Provider Data Catalog, Timely and Effective Care - Hospital (July 2026 release) - From research
California hospitals with longer ED times tended to have more patients leave unseen
CMS Provider Data Catalog, Timely and Effective Care - Hospital (July 2026 release) - From research
Transfers out of California EDs took a median 398 minutes, 111 more than nationally
CMS Provider Data Catalog, Timely and Effective Care - State (July 2026 release); CMS Provider Data Catalog, Timely and Effective Care - National (July 2026 release) - From research
California's discharged ED patients: median 174 minutes; 11 states and DC were longer
CMS Provider Data Catalog, Timely and Effective Care - State (July 2026 release); CMS Provider Data Catalog, Timely and Effective Care - National (July 2026 release)
Related facts
144 min
median minutes in the ED for patients sent home at low-volume EDs, California, October 2024 to September 2025
At California's low-volume EDs, patients sent home spent a median of 144 minutes in the ED, against 123 minutes at low-volume EDs nationally, from October 1, 2024 to September 30, 2025 (CMS measure OP-18b, low volume group).
Source: CMS Provider Data Catalog, Timely and Effective Care - State (July 2026 release).
KentApplied69 to 413 min
median minutes in the ED for patients sent home, fastest to slowest of 267 California hospitals, October 2024 to September 2025
The 267 California hospitals with a reported ED time for patients sent home ranged from 69 to 413 minutes, from October 1, 2024 to September 30, 2025, and the middle half fell between 146.5 and 208.5 minutes (CMS measure OP-18b, by Kent Applied's count).
Source: CMS Provider Data Catalog, Timely and Effective Care - Hospital (July 2026 release).
KentApplied398 min
median minutes in the ED before a transfer to another facility, California, October 2024 to September 2025
Patients transferred from a California emergency department to another facility spent a median of 398 minutes in the ED first, against 287 minutes nationally, from October 1, 2024 to September 30, 2025 (CMS measure OP-18d).
Source: CMS Provider Data Catalog, Timely and Effective Care - State (July 2026 release).
KentApplied
Sources for the figures above: CMS Provider Data Catalog, Timely and Effective Care - State (July 2026 release) (opens in a new tab); CMS Provider Data Catalog, Timely and Effective Care - National (July 2026 release) (opens in a new tab).
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