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 54 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. Margaret Chen, M.DEscondido, CA 920251659305084
  2. Mark Chen, MDSan Francisco, CA 941151891989190
  3. Mary Chen, M.D.Walnut, CA 917891568445229
  4. Max Chen, M.D.Vista, CA 920831285750356
  5. Melanie Chen, MD, MPHWest Hollywood, CA 900481275112351
  6. Melinda Chen, MDLa Jolla, CA 920371942396197
  7. Michael Chen, M.D.Downey, CA 902421629217138
  8. Michael Chen, MDFontana, CA 923351306913256
  9. Naihsien Chen, M.D.Modesto, CA 953551174699755
  10. Naili Chen, D.O., MPH, MASCLancaster, CA 935341649251661
  11. Nan Chen, M.D.Alhambra, CA 918011174750897
  12. Nancy Chen, M.D.San Jose, CA 951251306103742
  13. Pai-Hsiang Chen, D.OArcadia, CA 910071063405892
  14. Patricia Chen, MDCitrus Heights, CA 956101568447621
  15. Patrick Chen, M.D.Salinas, CA 939011598749616
  16. Paul Chen, M.D.Rialto, CA 923761588689350
  17. Phoebe Chen, M.D.San Luis Obispo, CA 934011528163870
  18. Qingzheng Chen, MDSan Jose, CA 951281265069850
  19. Sandar Chen, MDEl Monte, CA 917311255747069
  20. Shaw Chen, M.D.Los Angeles, CA 900331043233281
  21. Sheree Chen, M.D.Panorama City, CA 914021891140901
  22. Shih Fan Chen, DOBaldwin Park, CA 917061922252923
  23. Shu Chen, MDSacramento, CA 958191467541987
  24. Si Chen, M.D.Bakersfield, CA 933061467794180
  25. Stephanie Chen, MDDowney, CA 902421730352121
  26. Stephen Chen, M.D.Downey, CA 902421083844179
  27. Stephen Chen, M.D.Oakland, CA 946121265601553
  28. Steve Chen, MDSan Diego, CA 921211457385759
  29. Tan Chen, MDFresno, CA 937201477693927
  30. Ted Chen, MDBellflower, CA 907061548312853
  31. Thomas Chen, M.D.Riverside, CA 925061053329227
  32. Thomas Chen, M.D.Oakland, CA 946021699112458
  33. Tianyu Chen, MDOrange, CA 928681164927463
  34. Tom ChenEncino, CA 914361215514260
  35. Tsuh-Yin Chen, MDSan Diego, CA 921041093803520
  36. Victoria Chen, M.D.Baldwin Park, CA 917061760423016
  37. Victoria Chen, MDMenlo Park, CA 940251073705067
  38. Wei Chen, D.O.Arcadia, CA 910061487800173
  39. Wei Chen, MDSan Jose, CA 951281013190370
  40. Wei-Tzuoh Chen, MDVisalia, CA 932771184732398
  41. Weip Chen, M.D.Redondo Beach, CA 902771295754281
  42. William Chen, M.D.Irvine, CA 926181881659142
  43. William Chen, MDSan Pablo, CA 948061851498372
  44. Xiaochuan Chen, M.D.Hayward, CA 945451750549614
  45. Xiaoshan ChenMilpitas, CA 950351548840846
  46. Yanfei Chen, MDColton, CA 923241437103322
  47. Yi-Fen Chen, MDSanta Clara, CA 950511073692711
  48. Yihan ChenLos Angeles, CA 900951730508367
  49. Yudu Chen, MDAnaheim, CA 928071083781132
  50. Yuen Chen, MDVacaville, CA 956871407925605

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.