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 233 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. Kuo Ooi, M.D.Rocklin, CA 956771598775421
  2. Suma Oommen, M.D.Lake Forest, CA 926301063431203
  3. Dozie Oparaugo, DOOroville, CA 959661720643083
  4. Michael Opene, M.D.Burbank, CA 915051851827471
  5. Alfred Oppenheim, M.D.Corte Madera, CA 949251023028917
  6. Karen Oppenheimer, M.D.Torrance, CA 905031164430443
  7. Lucian Oprea, MD.El Centro, CA 922431033329792
  8. Alexandra Orchard, MD, PHDSylmar, CA 913421649929076
  9. Tiffany Ordonez, M.D.Garberville, CA 955421588754006
  10. Serena Organ, DOLong Beach, CA 908061376278671
  11. Elmas Orhan, NURSE PRACTITIONERBakersfield, CA 933061750035432
  12. Adrian Oribello, M.D.Jackson, CA 956421912102922
  13. Anige'r Oriol, MDLos Angeles, CA 900951437890712
  14. Kevin Orita, MDFresno, CA 937221073076139
  15. Hedda Orkin, MDSan Francisco, CA 941101093753030
  16. Jennie Orland, M.D.San Francisco, CA 941101225256092
  17. Thomas Ormiston, MDSan Jose, CA 951281982709440
  18. Jelyca OrmondSan Jose, CA 951101396325916
  19. Monica Ormsby, MDPoway, CA 920641639270366
  20. Joyce Orndorff, M.D.Campbell, CA 950081730493693
  21. Richard OrnelasSan Jose, CA 951281730258229
  22. Carlos Irwin OronceLos Angeles, CA 900731649625245
  23. Nadia Orosz, M.D.Mountain View, CA 940401316367329
  24. Harold Orr, MDOakland, CA 946051861822819
  25. J Margo Orr, M.D.Irvine, CA 926181396848941
  26. Norman Orr, D.O.Wildomar, CA 925951871859553
  27. Sharon Orrange, M.D.Beverly Hills, CA 902111316983406
  28. Greg Orshansky, MDLos Angeles, CA 900731568478709
  29. Christina Ortega-ChenLos Angeles, CA 900271619266590
  30. Analiy Ortiz, MDSacramento, CA 958171679205835
  31. Jeff Ortiz, MDWalnut Creek, CA 945961891873964
  32. Paola Ortiz, MDTorrance, CA 905051457937963
  33. Charmaine Ortizo, M.D.Loma Linda, CA 923541689051120
  34. Kazumasa OsatoTorrance, CA 905051134748015
  35. Appledene Osbourne, MDSan Francisco, CA 941431164059143
  36. Mark Oscherwitz, MDSan Francisco, CA 941091437225059
  37. Edgardo Osea, M.D.Carson, CA 907451699795476
  38. Ebunoluwa Oshinuga-Atere, MDWalnut Creek, CA 945981083349609
  39. Rosalia Osias, M.D.Anaheim, CA 928041669582938
  40. Ali Osman, MDApple Valley, CA 923071891348678
  41. Debra Osman, MDSan Francisco, CA 941091730141573
  42. Faraaz Osmani, M.D.Encino, CA 914361588005474
  43. Mohammad Osmani, MDRedlands, CA 923731568479483
  44. Eduard Osmonov, MDWoodland Hills, CA 913671548329121
  45. Jessica OsorioTorrance, CA 905021457938250
  46. Tatiana Ososkova, MDSan Jose, CA 951231023281904
  47. Tiffany Ossi, MDWest Hollywood, CA 900481235889429
  48. Jennifer Oster, DO, MPHLos Angeles, CA 900641548816937
  49. Isabel OstrerSan Francisco, CA 941101912587726
  50. Robert Ostroff, M.D.Petaluma, CA 949541912109240

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.