NPPES file of Aug 9, 2026

Internal Medicine Physician in California

17,696 NPPES records list internal medicine physician with a practice address in California, 45 per 100,000 residents, the 17th highest rate of 51. Los Angeles and San Francisco have the most; each record links to the provider's NPI and the California license search. Page 230 of 354.

CMS NPPES registry, file of Aug 9, 2026; 2023 Census estimates · NUCC 207R00000X · method

Written with AI tools from the named public files; every figure is computed from those files (how it is made).

Los Angeles has the most, 1,423

  1. Los Angeles1,423
  2. San Francisco1,318
  3. San Diego961
  4. Sacramento601
  5. Oakland432

Internal Medicine Physician records in California

  1. Brian O'Neill, M.D.Martinez, CA 945531366425985
  2. Daniel O'Neill, MDSan Francisco, CA 941091588007926
  3. Timothy O'Neill, M.D.San Diego, CA 921031831172295
  4. Maeve O'Regan, MDWalnut Creek, CA 945981871535203
  5. Courtney O'Rourke, DOSan Diego, CA 921311730118886
  6. Geraldine O'Shea, DOJackson, CA 956421013910140
  7. Filadelfo Oandasan, M.D.Tracy, CA 953781396955035
  8. Sy Oang, D.O.Whittier, CA 906031972692937
  9. Cameron Oba, M.D.San Jose, CA 951241851357917
  10. Chisato Oba, M.D.Arcadia, CA 910061669476651
  11. Nashwan Obad, M.D.French Camp, CA 952311689155962
  12. Abiodun Obadina, M.D.,Atascadero, CA 934221790852945
  13. Hannah ObasiLos Angeles, CA 900331649775719
  14. Sara Obeid, MD, MPHOakland, CA 946021619400678
  15. Meena Oberoi, M.D.Torrance, CA 905051831125434
  16. Alisa Oberschelp, M.D.San Francisco, CA 941021487759007
  17. Linda Oberstein, MDBurlingame, CA 940101851483127
  18. Francis Obi, D.O.Los Angeles, CA 900111841659174
  19. Jessica Obi, MDMoreno Valley, CA 925531457094971
  20. Ikechi Obiocha, MDRialto, CA 923761467479295
  21. Udoh Obioha, MDSan Bernardino, CA 924101154366946
  22. Janet Obrien, M.D.Sacramento, CA 958351467702399
  23. Fabiola Ochoa, MDSylmar, CA 913421568826956
  24. Paloma Ochoa, M.D.Santa Barbara, CA 931051366189011
  25. William Ochoa, MDMoreno Valley, CA 925551558574954
  26. Lisa Ochoa-Frongia, M.D.San Francisco, CA 941101144529405
  27. Arman Odabas, MDStanford, CA 943051992449961
  28. Tomio Odama, M.D.Lodi, CA 952401437292612
  29. Gulnar Odera, MDPalo Alto, CA 943041578721015
  30. Abayomi Odubela, M.D.Murrieta, CA 925621922108877
  31. Rudolph Oehm, MDOakland, CA 946111699971689
  32. Matthew OertliSan Francisco, CA 941431811215338
  33. Leslie OesterichTorrance, CA 905091245518422
  34. Terence Offenberger, MDAliso Viejo, CA 926561023009586
  35. Timothy Offensend, MDSan Mateo, CA 944011083667539
  36. Ijeoma Ofiaeli, M.D.Santa Maria, CA 934581932138179
  37. David Ofman, MDSan Francisco, CA 941021619176120
  38. Marc Ofstein, M.D.Long Beach, CA 908221831117878
  39. Araksi Oganesian, M.D.Mission Hills, CA 913451730613183
  40. Buzand OganesianColton, CA 923241568049591
  41. Janna Oganessian, M.D.Tarzana, CA 913561801820832
  42. Mihran Ogaryan, MDPanorama City, CA 914021780324533
  43. Rita Ogbo, MDEl Monte, CA 917331174625990
  44. Chinelo OgboguLos Angeles, CA 900031326145343
  45. Akunna Ogbu, M.D.Los Angeles, CA 900241780858829
  46. David Ogden, M.D.San Anselmo, CA 949601003887324
  47. Ikuko Ogihara, MDSouth San Francisco, CA 940801740368372
  48. Kevin Ogrady, M.D.Newport Coast, CA 926571609060615
  49. Isaac Ogunmola, MDStanford, CA 943051538737390
  50. Charlene Oh, MDSylmar, CA 913421326240003

Source: CMS NPPES, primary taxonomy 207R00000X: records by practice city and the list of records, file of Aug 9, 2026.

California ranks 17 of 51 per resident

  1. New Jersey50
  2. New Hampshire48
  3. Minnesota46
  4. California45
  5. Florida45
  6. Ohio45
  7. 50 states and D.C.44

Source: CMS NPPES, primary taxonomy 207R00000X by practice state, file of Aug 9, 2026; records per 100,000 residents, 2023 Census estimates.

79.5% of these records appear in a Medicare file, against 78.7% nationally

A Medicare file here is Part D prescribing (2024), a MIPS score (2023), an Open Payments record (2024) or Medicare group billing (CMS Doctors and Clinicians). A record outside them may still see patients: these files cover Medicare only.

  1. California79.5%
  2. United States78.7%

Internal Medicine Physician records in California, measured

  • In a Medicare file14,068 of 17,696 · 79.5% here, 78.7% nationally
  • In the CMS Doctors and Clinicians file11,077 · 62.6% here, 61.4% nationally
  • Not updated in five years or more10,832 · 61.2% here, 55.4% nationally
  • Median graduation year2004 · the 11,065 records with a school on file

Source: CMS NPPES, file of Aug 9, 2026 (primary taxonomy 207R00000X); CMS Medicare Part D Prescribers 2024, MIPS 2023, Open Payments 2024 and Doctors and Clinicians, matched by NPI.

What the count covers

17,696 NPPES records list internal medicine physician (207R00000X) as their primary taxonomy with a practice address in California: 45 per 100,000 residents against 44 nationally (50 states and D.C.). Los Angeles has 1,423 of them (8%).

A record is a registration a provider made and keeps up to date: it shows neither that the provider is licensed nor that they still practice there. The state's own license search is the check.

States with a similar number

  1. New York12,067
  2. Florida10,151
  3. Texas9,175
  4. Pennsylvania7,300

States with a similar rate per 100,000

  1. Minnesota45.9
  2. Ohio44.8
  3. New Hampshire48.0
  4. Maine42.8

The largest states

  1. New York12,067
  2. Florida10,151
  3. Texas9,175
  4. Pennsylvania7,300
  5. Illinois7,238

Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy; 2023 Census population estimates. A registry record is not a license.

Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.