NPPES file of Aug 9, 2026

Clinical Pathology/Laboratory Medicine Physician in California

131 NPPES records list clinical pathology/laboratory medicine physician with a practice address in California, 0.3 per 100,000 residents, the 27th highest rate of 49. San Francisco and Los Angeles have the most; each record links to the provider's NPI and the California license search. Page 3 of 3.

CMS NPPES registry, file of Aug 9, 2026; 2023 Census estimates · NUCC 207ZP0105X · method

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

San Francisco has the most, 28

  1. San Francisco28
  2. Los Angeles17
  3. San Diego10
  4. San Luis Obispo7
  5. West Hollywood7

Clinical Pathology/Laboratory Medicine Physician records in California

  1. Jonathan Pollack, MD, PHDStanford, CA 943051124857503
  2. Sharmila Pramanik, MDSan Jose, CA 951281730284936
  3. Nicholas Protopsaltis, MD, PHDSan Diego, CA 921031275160632
  4. Bruce Ragsdale, M.D.San Luis Obispo, CA 934011225072374
  5. Saravanan Raju, MDSan Diego, CA 921031679199111
  6. Elaine ReedLos Angeles, CA 900951376385898
  7. Jon Ross, MDSan Francisco, CA 941181649248337
  8. Iris Schrijver, M.D.Stanford, CA 943051508058538
  9. Michael Selsted, MDLos Angeles, CA 900891629158878
  10. Hedyeh Shafi, M.D.West Hollywood, CA 900481487963690
  11. Mrugesh Shah, M.D.Thousand Oaks, CA 913601720208499
  12. Raul Simental-Pizarro, M.D.Los Angeles, CA 900331255656831
  13. Preston Simpson, MDFresno, CA 937201265453021
  14. Rashida Soni, M.D.Ventura, CA 930031619034311
  15. Jacob Spector, MDSan Francisco, CA 941071245693456
  16. Elizabeth St. Lezin, M.D.San Francisco, CA 941211477580314
  17. Glen StewartMartinez, CA 945531417016742
  18. John Thorson, MD, PHDSan Diego, CA 921031225120454
  19. Erron Titus, MD, PHDSan Francisco, CA 941431841828134
  20. Tai-Po Tschang, MDFresno, CA 937201548287543
  21. Kristen Turowski, SLPAPalmdale, CA 935501326686874
  22. Xander Van Wijk, PHD, DABCC, FADLMSan Francisco, CA 941071487460341
  23. Frederic Waldman, MDSan Francisco, CA 941431053377424
  24. Dawn Ward, M.D.Los Angeles, CA 900951508291402
  25. Eva Wasef, M.D.Bishop, CA 935141699744813
  26. Kwun Wen, M.D.San Francisco, CA 941431326307430
  27. Wendy Wu, MDSan Jose, CA 951281205922952
  28. Yi Xie, M.D.Los Angeles, CA 900331841425378
  29. He Yang, PHDValencia, CA 913541417509266
  30. Barbara Yost-Knox, MDStockton, CA 952101598839193
  31. Alyssa Ziman, MDLos Angeles, CA 900951487684700

Source: CMS NPPES, primary taxonomy 207ZP0105X: records by practice city and the list of records, file of Aug 9, 2026.

California ranks 27 of 49 per resident

  1. Alabama0.4
  2. Florida0.4
  3. Wyoming0.3
  4. California0.3
  5. North Carolina0.3
  6. Vermont0.3
  7. 50 states and D.C.0.4

Source: CMS NPPES, primary taxonomy 207ZP0105X by practice state, file of Aug 9, 2026; records per 100,000 residents, 2023 Census estimates.

35.9% of these records appear in a Medicare file, against 49.3% 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. California35.9%
  2. United States49.3%

Clinical Pathology/Laboratory Medicine Physician records in California, measured

  • In a Medicare file47 of 131 · 35.9% here, 49.3% nationally
  • In the CMS Doctors and Clinicians file40 · 30.5% here, 41.7% nationally
  • Not updated in five years or more83 · 63.4% here, 65.6% nationally
  • Median graduation year1998 · the 40 records with a school on file

Source: CMS NPPES, file of Aug 9, 2026 (primary taxonomy 207ZP0105X); CMS Medicare Part D Prescribers 2024, MIPS 2023, Open Payments 2024 and Doctors and Clinicians, matched by NPI.

What the count covers

131 NPPES records list clinical pathology/laboratory medicine physician (207ZP0105X) as their primary taxonomy with a practice address in California: 0.3 per 100,000 residents against 0.4 nationally (50 states and D.C.). San Francisco has 28 of them (21%).

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 York102
  2. Pennsylvania86
  3. Florida83
  4. Wisconsin80

States with a similar rate per 100,000

  1. North Carolina0.3
  2. Colorado0.3
  3. Alabama0.4
  4. Maryland0.4

The largest states

  1. New York102
  2. Pennsylvania86
  3. Florida83
  4. Wisconsin80
  5. Minnesota79

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.