NPPES file of Aug 9, 2026

Research Study Specialist in California

82 NPPES records list research study specialist with a practice address in California, 0.2 per 100,000 residents, the 8th highest rate of 41. Los Angeles and Palo Alto have the most; each record links to the provider's NPI and the California license search. Page 2 of 2.

CMS NPPES registry, file of Aug 9, 2026; 2023 Census estimates · NUCC 1744R1102X · 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, 8

  1. Los Angeles8
  2. Palo Alto8
  3. San Francisco6
  4. Oakland4
  5. Davis3

Research Study Specialist records in California

  1. Joseph PaulsonSan Francisco, CA 941021275382277
  2. Vu Phung, MDBakersfield, CA 933121063127934
  3. Alysa PiarLos Angeles, CA 900161740031103
  4. Sebastian PinteaPalo Alto, CA 943051548133309
  5. Bradley Pollock, PHD, MPHDavis, CA 956161801724158
  6. Marzia Rigolli, MD, DPHILSan Diego, CA 921211104788090
  7. John RivieSan Francisco, CA 941021801217484
  8. Laura Romo, MPHSan Francisco, CA 941101093259012
  9. Gina Roque Torres, DDSLoma Linda, CA 923501124987516
  10. Michael Ruderman, DO, MPHOakland, CA 946091902259880
  11. Fabian Sanchis Gomar, MD, PHDSan Jose, CA 951281346007226
  12. Yaritza Santos, MDBakersfield, CA 933011154145100
  13. Olusola Sanwo, M.D., MPHLong Beach, CA 908221881847663
  14. Sye-Ok SatoOakland, CA 946121003344847
  15. Diego Schiffino, MDAgoura Hills, CA 913011417824426
  16. Neda Shokrai, MDFoster City, CA 944041629380829
  17. Martha Shumway, PH.D.San Francisco, CA 941101376967455
  18. Mariella Simon, MS CGCIrvine, CA 926971235154485
  19. Alan Smith, PHD, MPHSan Diego, CA 921201245359397
  20. Tara SmithCarpinteria, CA 930131124970165
  21. Andrew SomersHollywood, CA 900281730701640
  22. Isaiah SorotenDublin, CA 945681326896838
  23. Courtney Stephens, MBALong Beach, CA 908021093099632
  24. Clifford StevensonAlamo, CA 945071194235200
  25. Roshan Swaroop, MSStanford, CA 943051952246092
  26. Laurel Te VeldeNovato, CA 949491568079887
  27. Ajit Varki, MBBSLa Jolla, CA 920931023676632
  28. Filipinas VitugBuena Park, CA 906201396162145
  29. Lena Walker, STUDENTPomona, CA 917671093913121
  30. Spencer Williams, B.A.San Francisco, CA 941101790806362
  31. Xin ZhangSan Jose, CA 951121598206732
  32. Nicholas Zoffel, PH.D.Sacramento, CA 958181124874748

Source: CMS NPPES, primary taxonomy 1744R1102X: records by practice city and the list of records, file of Aug 9, 2026.

California ranks 8 of 41 per resident

  1. Delaware0.3
  2. Colorado0.3
  3. Iowa0.2
  4. California0.2
  5. Kansas0.2
  6. Connecticut0.2
  7. 50 states and D.C.0.1

Source: CMS NPPES, primary taxonomy 1744R1102X by practice state, file of Aug 9, 2026; records per 100,000 residents, 2023 Census estimates.

3.7% of these records appear in a Medicare file, against 4.3% 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. California3.7%
  2. United States4.3%

Research Study Specialist records in California, measured

  • In a Medicare file3 of 82 · 3.7% here, 4.3% nationally
  • In the CMS Doctors and Clinicians file1 · 1.2% here, 0.9% nationally
  • Not updated in five years or more43 · 52.4% here, 66.7% nationally

Source: CMS NPPES, file of Aug 9, 2026 (primary taxonomy 1744R1102X); CMS Medicare Part D Prescribers 2024, MIPS 2023, Open Payments 2024 and Doctors and Clinicians, matched by NPI.

What the count covers

82 NPPES records list research study specialist (1744R1102X) as their primary taxonomy with a practice address in California: 0.2 per 100,000 residents against 0.1 nationally (50 states and D.C.). Los Angeles has 8 of them (10%).

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. Florida33
  2. Texas33
  3. Maryland31
  4. Massachusetts25

States with a similar rate per 100,000

  1. Colorado0.3
  2. Missouri0.2
  3. Arizona0.1
  4. North Carolina0.1

The largest states

  1. Florida33
  2. Texas33
  3. Maryland31
  4. Massachusetts25
  5. New York25

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.