California ambulatory surgical centers: 645 Medicare-certified, ASC quality measures with NPI bridge.
Per-facility ASC-1 through ASC-12 quality measures with deterministic NPI bridge (100.0% NPI coverage in California) — the only Care Compare facility type with a usable provider-identity join key.
Editorial note: California has dense local journalism + Leapfrog coverage of outpatient surgery; Fonteum's contribution is the per-facility ASC-1-12 + NPI data layer, not editorial commentary.
ASC-12 performance breakdown — California
ASC-12 measures hospital-visit rate within 7 days of outpatient surgery. CMS-published performance categories on facilities meeting the volume threshold.
ASC-1 through ASC-11 quality measures — California state means
Each row is the mean CMS-published rate across Californiafacilities that meet the measure’s reporting threshold. Lower is better for adverse-event measures; higher is better for the prophylactic-antibiotic process measure. Facilities CMS suppressed for low case volume are excluded from the mean, not counted as zero.
| Measure | Direction | State mean | Facilities reporting |
|---|---|---|---|
| Patient burn rate | Lower is better | 0.00% | 284 |
| Unplanned hospital transfer/admission | Lower is better | 0.02% | 327 |
| Wrong site, side, patient, or procedure | Lower is better | 0.00% | 294 |
| All-cause hospital readmission rate | Lower is better | 0.08% | 363 |
| Appropriate prophylactic antibiotic use | Higher is better | 78.99% | 209 |
| Cataract surgery complication rate | Lower is better | 80.62% | 24 |
Highest-volume ASCs — California
Top 25 by ASC-12 reportable case volume (a procedural-volume signal, not a quality measure).
| Facility | City | ASC-12 cases | Category |
|---|---|---|---|
| Monterey bay endoscopy center llc | MONTEREY | 6275 | No Different Than the National Rate |
| Mirage endoscopy center lp | RANCHO MIRAGE | 6258 | Better Than the National Rate |
| Fresno ca endoscopy asc lp | FRESNO | 5773 | No Different Than the National Rate |
| Santa maria digestive diagnostic center | SANTA MARIA | 5351 | No Different Than the National Rate |
| Sansum clinic | SANTA BARBARA | 4865 | No Different Than the National Rate |
| Redding endoscopy center | REDDING | 4739 | No Different Than the National Rate |
| Pasadena endoscopy center inc | PASADENA | 4461 | No Different Than the National Rate |
| Sutter roseville endoscopy center | ROSEVILLE | 4017 | No Different Than the National Rate |
| San francisco endoscopy center llc | SAN FRANCISCO | 3966 | No Different Than the National Rate |
| Hoag endoscopy center | NEWPORT BEACH | 3830 | No Different Than the National Rate |
| Sierra endoscopy center | GRASS VALLEY | 3593 | No Different Than the National Rate |
| East bay endosurgery | OAKLAND | 3476 | No Different Than the National Rate |
| Palo alto medical foundation camino surgery division | MOUNTAIN VIEW | 3466 | No Different Than the National Rate |
| Newport beach orange coast endoscopy | NEWPORT BEACH | 3402 | No Different Than the National Rate |
| Glbesc llc dba memorialcare outpatient surgical center long beach | LONG BEACH | 3364 | Better Than the National Rate |
| Surgecenter of palo alto | PALO ALTO | 3301 | No Different Than the National Rate |
| Folsom sierra endoscopy center | FOLSOM | 3171 | No Different Than the National Rate |
| Hoag endoscopy center irvine | IRVINE | 3094 | No Different Than the National Rate |
| Truxtun surgery center inc | BAKERSFIELD | 3081 | No Different Than the National Rate |
| Aspen surgery center llc dba aspen surgery center | WALNUT CREEK | 2955 | No Different Than the National Rate |
| Mid peninsula endoscopy | BURLINGAME | 2882 | No Different Than the National Rate |
| The endoscopy center | YUBA CITY | 2865 | No Different Than the National Rate |
| Los robles surgicenter llc | THOUSAND OAKS | 2824 | No Different Than the National Rate |
| Golden gate endoscopy center llc | SAN FRANCISCO | 2773 | No Different Than the National Rate |
| Valley endoscopy center | TARZANA | 2678 | No Different Than the National Rate |
California ambulatory surgical centers — FAQ
- How many ambulatory surgical centers are Medicare-certified in California?
- 645 Medicare-certified ambulatory surgical centers operate in California as of the CMS Care Compare ASC Quality snapshot (2026-05-07). Every facility carries a National Provider Identifier — ASCs are the only Care Compare facility type with a 100% deterministic NPI bridge.
- What ASC quality measures does California report?
- CMS publishes ASC-1 through ASC-12. This page aggregates the state mean for the per-facility rate measures that have at least one reporting facility in California, plus the ASC-12 colonoscopy follow-up performance category. Measures are CMS-published rates: lower is better for adverse-event measures (burns, transfers, wrong-site events, readmissions, cataract complications) and higher is better for appropriate prophylactic antibiotic use.
- Why are some facilities missing a quality rate?
- CMS suppresses a measure when a facility falls below the minimum case volume for that measure in the reporting window. Suppressed facilities are excluded from each state mean rather than counted as zero, so the averages reflect only facilities CMS actually scored.
- Where does this ASC data come from and how current is it?
- The displayed fields come from the CMS Care Compare Ambulatory Surgical Center Quality file, source-modified 2025-12-16. Record-level provenance can be null; cross-check a consequential facility record at Medicare.gov.
Compare other facility types
Supported Care Compare facility responses for California and other states expose source-and-date fields where the module supplies them; individual fields may be absent or null.