Darwin C. Tsang, O.D.
Optometrist · Petaluma, CA
Darwin C. Tsang, O.D. is an optometrist with a practice address in Petaluma, California, and NPI 1619344918, issued on Aug 21, 2015. Check the license (California 15225 TLG, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Darwin C. Tsang
- Credential
- O.D.
- Primary taxonomy
- Optometrist 152W00000X
- License number
- 15225 TLG CA
Self-reported in NPPES; status is on the state search - Practice location
- 401 Kenilworth Dr, Petaluma, CA 94952
- Phone
- (707) 775-6022
- Enumerated
- Aug 21, 2015
- Record last updated
- Sep 23, 2016 (not updated in 10 years: call before relying on the address or phone)
- Fax
- (707) 782-0568
- Medicare enrollment
- Enrolled (PECOS I20151229002601); accepts Medicare assignment
- Medical or professional school
- New England College Of Optometry, 2015
- Entity
- Type 1 · individual
8 nearest optometrist records → All 8,308 in California → Look up another NPI →
Also registered at 401 Kenilworth Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Humara AnwarPharmacist1699191759
- Nicholas LauPharmacist1679909196
- Lauren Louie, PHARM. D.Pharmacist1043628951
- Melissa Styles, D.D.SDentist1932518164
- Thomas Szutz, D.D.S.Dentist1043507627
- Kristi Rose WongPharmacist1003352030
Verify Darwin C. Tsang in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license 15225 TLGCheck the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
94% fewer Medicare Part D claims than the average optometrist in 2024
17 Medicare Part D claims, against an average of 277 among the 33,128 providers of this specialty who prescribed in Part D.
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.
Industry payments in 2024: $188.69
7 payments; by number, the most common kind was food and beverage; the largest payer was Alcon Vision LLC. The 34,453 providers of this specialty with any payment received $769.99 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Marin Optometric Group IncSan Rafael, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Darwin C. Tsang among 8,308 optometrist records in California
Darwin C. Tsang, O.D. is one of 8,308 optometrist records with a practice address in California. 67% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2015, is newer than 71% of them.
- NPI issued2015 · 71% of these records are older, 27% newer
- In a Medicare fileYes · 67% of these records are
- In the CMS Doctors and Clinicians fileYes · 43% of these records are
- Graduated2015 · median 2008 among the 3,573 with a school on file
- Record last updated2016 · 67% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 152W00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Optometrist providers in California
There are 8,308 optometrist records in California.
All 8,308 in California → Every provider in Petaluma → Optometrist nationwide →
The 8 optometrist records with the nearest ZIP codes
- Jean Brennan, O.D.Petaluma, CA 949521740321710
- Mina Chen, ODPetaluma, CA 949521982263265
- Karen Griffith, ODPetaluma, CA 949521659372365
- Htoo Htoo Lu, ODPetaluma, CA 949521811547656
- Gerald Pittler, O.D.Petaluma, CA 949521699708727
- Kelly Staton, O.D.Petaluma, CA 949521548302649
- Gordon Wong, ODPetaluma, CA 949521417949942
- Richard Aston, O.D.Petaluma, CA 949541518939156
Common questions
What is Darwin C. Tsang, O.D.'s NPI number?
Darwin C. Tsang, O.D.'s National Provider Identifier (NPI) is 1619344918, issued on Aug 21, 2015. An NPI identifies a provider in billing; it is not a license.
Where is Darwin C. Tsang, O.D. located?
The NPPES record lists a practice address at 401 Kenilworth Dr, Petaluma, CA, 94952. Phone: (707) 775-6022. Providers update this record themselves, so call before visiting.
How can I verify Darwin C. Tsang, O.D.'s license?
NPPES lists California license number 15225 TLG, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Darwin C. Tsang, O.D. prescribe under Medicare Part D?
In 2024, Darwin C. Tsang, O.D. had 17 Medicare Part D claims; the average among optometrist prescribers was 277. 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.