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The 7 largest US health systems by physicians on the Medicare clinician file (September 2026)
Updated 15 September 2026
Kaiser Permanente carries 16,648 physicians on the CMS clinician file, 2.3% of the 730,327 physicians on it.
Source: ProfessionLens, September 2026. CMS Doctors and Clinicians national file, released 10 September 2026.
| Rank | Health system | Physicians | Share of file | Scope |
|---|---|---|---|---|
| 1 | Kaiser Permanente | 16,648 | 2.3% | United States |
| 2 | Mayo Clinic | 5,945 | 0.8% | United States |
| 3 | Sutter Health | 4,454 | 0.6% | United States |
| 4 | Cleveland Clinic | 4,448 | 0.6% | United States |
| 5 | Northwell Health | 3,929 | 0.5% | United States |
| 6 | UPMC | 3,166 | 0.4% | United States |
| 7 | Intermountain Health | 2,828 | 0.4% | United States |
Only systems whose CMS facility names carry the system name can be counted this way. Systems whose clinicians enrol under unrelated practice names are not on this list.
Source: ProfessionLens, September 2026. CMS Doctors and Clinicians national file, released 10 September 2026.
Cite this
ProfessionLens, The 7 largest US health systems by physicians on the Medicare clinician file, September 2026, https://professionlens.com/lists/largest-health-systems-by-physicians.