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 232 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. Justin Olivas, MDSanta Clara, CA 950511891321709
  2. Deanna Oliver, MDSan Diego, CA 921181750725362
  3. Diane Oliver, MDSan Mateo, CA 944041902286735
  4. Kerry Oliver, M.D.Bakersfield, CA 933061356365373
  5. Devin Oller, MDSan Francisco, CA 941431023351897
  6. Mary Olomu, MDStanford, CA 943051982117628
  7. Christopher Olonan, MDSan Diego, CA 921031013050541
  8. Dagmara Olsen, MDPico Rivera, CA 906601356912059
  9. David Olson, MDOakdale, CA 953611346252525
  10. David Olson, M.D.Carmichael, CA 956081962422618
  11. Eric Olson, M.D.Chula Vista, CA 919111730151234
  12. Jeffrey Olson, M.D.Moreno Valley, CA 925571124386198
  13. Lauren Olson, MDSan Francisco, CA 941171639533961
  14. Robert Olson, M.DSalinas, CA 939011588661367
  15. Nneka Oluoha, M.DMoreno Valley, CA 925551770014615
  16. Michael Olvera, MDSacramento, CA 958171083364277
  17. Vanessa Olvera, MDSanta Monica, CA 904041407475122
  18. Ann Omachi, MDDaly City, CA 940151780743740
  19. Rodney Omachi, M.D.San Francisco, CA 941121811909096
  20. Julie Omelveny, MDBerkeley, CA 947051861579609
  21. Ronald Omino, M.D.Simi Valley, CA 930651871912451
  22. Olayinka Omololu, MDVisalia, CA 932911861445470
  23. Bahman Omrani, DOSherman Oaks, CA 914231700945417
  24. Meral Omurtag, M.D.La Jolla, CA 920371396834636
  25. Gerald Ondash, MDVista, CA 920831730102153
  26. Annie Ondracek, MDSan Diego, CA 921131528695541
  27. Ma Christina Ondrade, M.D.San Diego, CA 921201285836536
  28. Iwan Ong, MDRiverside, CA 925051265416739
  29. Melchor Ong, MDClovis, CA 936111245318070
  30. Michael Ong, MDLos Angeles, CA 900951598785776
  31. Michelle Ong, M.D.Orinda, CA 945631871671594
  32. Roger Ong, MDHarbor City, CA 907101881761799
  33. Samuel Ong, MDLakewood, CA 907121356373310
  34. Stephen Ong, M.D.San Francisco, CA 941151780750018
  35. Timothy Ong, MDSan Jose, CA 951281033125075
  36. Van Ong, D.O.Sunnyvale, CA 940861285990614
  37. Robin Onishi, MDLong Beach, CA 908221104837376
  38. Allen Onizuka, MDBaldwin Park, CA 917061811258940
  39. Ricky Onofre-Vasquez, M.D.Los Angeles, CA 900661750353892
  40. Pedro Ontiveros Jr., MDLos Angeles, CA 900341851450449
  41. Ada Onyeagocha, MDHarbor City, CA 907101932270964
  42. Anne Onyekwuluje, MDAnaheim, CA 928051649210493
  43. Aung Oo, M.DModesto, CA 953551285983601
  44. Khin Oo, MDPasadena, CA 911051588638043
  45. Nang Sein OoFrench Camp, CA 952311093501207
  46. Nicholas Oo, DOLos Angeles, CA 900331174379192
  47. Thein Oo, MDVictorville, CA 923951467404897
  48. Theingi Oo, MDLos Angeles, CA 900271366637407
  49. Thiri Oo, M.D.Claremont, CA 917111619256617
  50. Tun OoLancaster, CA 935341477973865

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.