Helen Woohee Yang, MD
Internal Medicine Physician · Castro Valley, CA
Helen Woohee Yang, MD is an internal medicine physician with a practice address in Castro Valley, California, and NPI 1003270877, issued on Apr 7, 2016. Check the license (California A153680, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Helen Woohee Yang
- Credential
- MD
- Primary taxonomy
- Internal Medicine Physician 207R00000X
- License number
- A153680 CA
Self-reported in NPPES; status is on the state search - Practice location
- 20642 John Dr, Castro Valley, CA 94546
- Phone
- (510) 806-2100
- Enumerated
- Apr 7, 2016
- Record last updated
- Apr 29, 2024
- Fax
- (323) 226-2657
- Medicaid ID
- HY3232267556 CA
- Medicare enrollment
- Enrolled (PECOS I20210421002849); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest internal medicine physician records → All 17,696 in California → Look up another NPI →
Also registered at 20642 John Dr
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Kalaokalani Chandler, M.D.Obstetrics & Gynecology Physician1164459947
- Shiven Chaudhry, MDInternal Medicine Physician1528594801
- Corina Clark, P.A.Physician Assistant1720480049
- Ashley Etchison, MDDiagnostic Radiology Physician1962907840
Verify Helen Woohee Yang in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A153680Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
64% fewer Medicare Part D claims than the average internal medicine physician in 2024
1,128 Medicare Part D claims for 352 beneficiaries, against an average of 3,176 among the 108,855 providers of this specialty who prescribed in Part D. Brand-name drugs were 14% of claims. 18 claims were for opioids.
Most prescribed
- Atorvastatin Calcium88 claims
- Amlodipine Besylate72 claims
- Levothyroxine Sodium46 claims
- Lisinopril33 claims
- Losartan Potassium33 claims
- Hydrochlorothiazide32 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.
Industry payments in 2024: $59.73
2 payments; by number, the most common kind was food and beverage; the largest payer was Meditrina. The 50,334 providers of this specialty with any payment received $1,303.06 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
- Alameda Health SystemOakland, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Helen Woohee Yang among 17,696 internal medicine physician records in California
Helen Woohee Yang, MD is one of 17,696 internal medicine physician records with a practice address in California. 79% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2016, is newer than 79% of them.
- NPI issued2016 · 79% of these records are older, 19% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 63% of these records are
- Graduated2016 · median 2004 among the 11,065 with a school on file
- Record last updated2024 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207R00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
24 internal medicine physician records list a practice address in Castro Valley
They are 24 of the 999 NPPES records with a practice address in Castro Valley, and 17,696 internal medicine physician records in California.
All 17,696 in California → Every provider in Castro Valley → Internal Medicine Physician nationwide →
The 8 internal medicine physician records with the nearest ZIP codes
- Nabil Abudayeh, MDCastro Valley, CA 945461699724484
- Monica Bhargava, MDCastro Valley, CA 945461619900347
- Wing Chin, M.D.Castro Valley, CA 945461124052576
- Richard Ho, M. D.Castro Valley, CA 945461548283005
- Kathryn Hodge, MDCastro Valley, CA 945461194741256
- Nidhi Johri, M.DCastro Valley, CA 945461285811489
- Samir Kadada, M.D.Castro Valley, CA 945461952315202
- Donald Knotts, MEDICAL DOCTORCastro Valley, CA 945461790858611
Common questions
What is Helen Woohee Yang, MD's NPI number?
Helen Woohee Yang, MD's National Provider Identifier (NPI) is 1003270877, issued on Apr 7, 2016. An NPI identifies a provider in billing; it is not a license.
Where is Helen Woohee Yang, MD located?
The NPPES record lists a practice address at 20642 John Dr, Castro Valley, CA, 94546. Phone: (510) 806-2100. Providers update this record themselves, so call before visiting.
How can I verify Helen Woohee Yang, MD's license?
NPPES lists California license number A153680, 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 Helen Woohee Yang, MD prescribe under Medicare Part D?
In 2024, Helen Woohee Yang, MD had 1,128 Medicare Part D claims for 352 beneficiaries; the average among internal medicine physician prescribers was 3,176. 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.