Gamin Mary Thomason, MD
Obstetrics & Gynecology Physician · Petaluma, CA
Gamin Mary Thomason, MD is an obstetrics & gynecology physician with a practice address in Petaluma, California, and NPI 1720162704, issued on Oct 25, 2006. Check the license (California G69086, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Gamin Mary Thomason
- Credential
- MD
- Primary taxonomy
- Obstetrics & Gynecology Physician 207V00000X
- License number
- G69086 CA
Self-reported in NPPES; status is on the state search - Practice location
- 3900 Lakeville Hwy, Petaluma, CA 94954
- Phone
- (707) 765-3900
- Enumerated
- Oct 25, 2006
- Record last updated
- Dec 22, 2021 (not updated in 5 years: call before relying on the address or phone)
- Medicaid ID
- 00G690860 CA
- Entity
- Type 1 · individual
8 nearest obstetrics & gynecology physician records → All 5,088 in California → Look up another NPI →
Also registered at 3900 Lakeville Hwy
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Matthew AndersonPharmacist1336673110
- Suzanne Aoyagi, PHARMDPharmacist1497289268
- John Arden, PHDPsychologist1841351053
- Caroline Barnhart, MDObstetrics & Gynecology Physician1437618774
- Alexis Becker, CNMMidwife1225112584
- Sharina Belani, MDInternal Medicine Physician1700958550
Verify Gamin Mary Thomason in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G69086Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
2.4 times the Medicare Part D claims of the average obstetrics & gynecology physician in 2024
399 Medicare Part D claims for 173 beneficiaries, against an average of 165 among the 28,733 providers of this specialty who prescribed in Part D. Brand-name drugs were 13% of claims.
Most prescribed
- Estradiol122 claims
- Progesterone53 claims
- Yuvafem35 claims
- Acyclovir26 claims
- Climara25 claims
- Dotti19 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Gamin Mary Thomason among 5,088 obstetrics & gynecology physician records in California
Gamin Mary Thomason, MD is one of 5,088 obstetrics & gynecology physician records with a practice address in California. 74% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 5% of them.
- NPI issued2006 · 5% of these records are older, 52% newer
- In a Medicare fileYes · 74% of these records are
- In the CMS Doctors and Clinicians fileNo · 53% of these records are
- Record last updated2021 · 64% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207V00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Obstetrics & Gynecology Physician providers in California
There are 5,088 obstetrics & gynecology physician records in California.
All 5,088 in California → Every provider in Petaluma → Obstetrics & Gynecology Physician nationwide →
The 8 obstetrics & gynecology physician records with the nearest ZIP codes
- Caroline Barnhart, MDPetaluma, CA 949541437618774
- Julie Clark, MDPetaluma, CA 949541346216389
- Kellie Corcoran, MDPetaluma, CA 949541760817258
- Laurie Dibble, MDPetaluma, CA 949541487738555
- Anthony Kosinski, M.D.Petaluma, CA 949541588656631
- Elmira Manoucheri, M.D.Petaluma, CA 949541942475710
- Bonni Massa, M.D.Petaluma, CA 949541508933607
- Judith McCarthy, MDPetaluma, CA 949541770667750
Common questions
What is Gamin Mary Thomason, MD's NPI number?
Gamin Mary Thomason, MD's National Provider Identifier (NPI) is 1720162704, issued on Oct 25, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Gamin Mary Thomason, MD located?
The NPPES record lists a practice address at 3900 Lakeville Hwy, Petaluma, CA, 94954. Phone: (707) 765-3900. Providers update this record themselves, so call before visiting.
How can I verify Gamin Mary Thomason, MD's license?
NPPES lists California license number G69086, as entered by the provider. Search the Medical Board of California at https://www.mbc.ca.gov/License-Verification/default.aspx. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Gamin Mary Thomason, MD prescribe under Medicare Part D?
In 2024, Gamin Mary Thomason, MD had 399 Medicare Part D claims for 173 beneficiaries; the average among obstetrics & gynecology physician prescribers was 165. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it 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.