Eunice Yi-Wen Tsai, M.D.
Dermatology Physician · Union City, CA
Eunice Yi-Wen Tsai, M.D. is a dermatology physician with a practice address in Union City, California, and NPI 1609070051, issued on Jun 12, 2007. Check the license (California A76239, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Eunice Yi-Wen Tsai
- Credential
- M.D.
- Primary taxonomy
- Dermatology Physician 207N00000X
- License number
- A76239 CA
Self-reported in NPPES; status is on the state search - Practice location
- 3553 Whipple RD, Union City, CA 94587
- Phone
- (510) 454-1000
- Enumerated
- Jun 12, 2007
- Record last updated
- Feb 11, 2022
- Fax
- (650) 723-7796
- Medicare enrollment
- Enrolled (PECOS I20071012000558); accepts Medicare assignment
- Medical or professional school
- Harvard Medical School, 2000
- Entity
- Type 1 · individual
8 nearest dermatology physician records → All 2,083 in California → Look up another NPI →
Also registered at 3553 Whipple RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Kristina Austin, M.D.Ophthalmology Physician1417007238
- Vijaya Basawaprasad, M.D.Internal Medicine Physician1588736326
Verify Eunice Yi-Wen Tsai in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A76239Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
72% more Medicare Part D claims than the average dermatology physician in 2024
1,370 Medicare Part D claims for 303 beneficiaries, against an average of 797 among the 12,802 providers of this specialty who prescribed in Part D. Brand-name drugs were 14% of claims.
Most prescribed
- Triamcinolone Acetonide113 claims
- Fluocinonide99 claims
- Hydrocortisone85 claims
- Acitretin70 claims
- Hydroxyzine Hcl69 claims
- Ketoconazole54 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.
Bills Medicare through one group practice
- Permanente Medical Group IncRichmond, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Eunice Yi-Wen Tsai among 2,083 dermatology physician records in California
Eunice Yi-Wen Tsai, M.D. is one of 2,083 dermatology physician records with a practice address in California. 83% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2007, is newer than 44% of them.
- NPI issued2007 · 44% of these records are older, 45% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated2000 · median 2006 among the 1,450 with a school on file
- Record last updated2022 · 58% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207N00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Dermatology Physician providers in California
There are 2,083 dermatology physician records in California.
All 2,083 in California → Every provider in Union City → Dermatology Physician nationwide →
The 8 dermatology physician records with the nearest ZIP codes
- Kimberly ChunUnion City, CA 945871316381304
- Jennifer Chwalek, MDUnion City, CA 945871407999667
- Michael Hardy, M.D.Union City, CA 945871437237203
- Gun Ho LeeUnion City, CA 945871871120576
- Lucy Liu, MDUnion City, CA 945871568951838
- Ari Udugama, M.D.Union City, CA 945871093893851
- Juliana Cinque, MDPleasanton, CA 945881083643084
- Minh Dang, MDPleasanton, CA 945881629058441
Common questions
What is Eunice Yi-Wen Tsai, M.D.'s NPI number?
Eunice Yi-Wen Tsai, M.D.'s National Provider Identifier (NPI) is 1609070051, issued on Jun 12, 2007. An NPI identifies a provider in billing; it is not a license.
Where is Eunice Yi-Wen Tsai, M.D. located?
The NPPES record lists a practice address at 3553 Whipple RD, Union City, CA, 94587. Phone: (510) 454-1000. Providers update this record themselves, so call before visiting.
How can I verify Eunice Yi-Wen Tsai, M.D.'s license?
NPPES lists California license number A76239, 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 Eunice Yi-Wen Tsai, M.D. prescribe under Medicare Part D?
In 2024, Eunice Yi-Wen Tsai, M.D. had 1,370 Medicare Part D claims for 303 beneficiaries; the average among dermatology physician prescribers was 797. 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.