Ryan Chang
Medical Oncology Physician · San Mateo, CA
Ryan Chang is a medical oncology physician with a practice address in San Mateo, California, and NPI 1164985263, issued on Apr 8, 2019. Check the license (California A179941, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Ryan Chang
- Primary taxonomy
- Medical Oncology Physician 207RX0202X
- License number
- A179941 CA
Self-reported in NPPES; status is on the state search - Practice location
- 218 DE Anza Blvd, San Mateo, CA 94402
- Phone
- (415) 514-7520
- Enumerated
- Apr 8, 2019
- Record last updated
- Aug 28, 2024
- Entity
- Type 1 · individual
8 nearest medical oncology physician records → All 447 in California → Look up another NPI →
Also registered at 218 DE Anza Blvd
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Kent Adler, M.D.Hematology & Oncology Physician1013074632
- Jennifer Brown, M.D.Hematology & Oncology Physician1740347350
- Karen Chee, M.D.Hematology & Oncology Physician1487637310
- Shu Yi Chen, RPHPharmacist1902401250
- Bradley Ekstrand, M.D., PH.D.Hematology & Oncology Physician1528125135
- Jelena Kao, MDHematology & Oncology Physician1932242062
Verify Ryan Chang in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A179941Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
93% fewer Medicare Part D claims than the average medical oncology physician in 2024
50 Medicare Part D claims for 12 beneficiaries, against an average of 703 among the 4,230 providers of this specialty who prescribed in Part D. Brand-name drugs were 32% of claims.
Most prescribed
- Prednisone15 claims
- Abiraterone Acetate14 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: $85.26
1 payment: food and beverage; the largest payer was Medtronic, Inc. The 3,343 providers of this specialty with any payment received $11,773.47 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.
Ryan Chang among 447 medical oncology physician records in California
Ryan Chang is one of 447 medical oncology physician records with a practice address in California. 82% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2019, is newer than 93% of them.
- NPI issued2019 · 93% of these records are older, 4% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileNo · 70% of these records are
- Record last updated2024 · 41% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RX0202X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Medical Oncology Physician providers in California
There are 447 medical oncology physician records in California.
All 447 in California → Every provider in San Mateo → Medical Oncology Physician nationwide →
The 8 medical oncology physician records with the nearest ZIP codes
- Matthew Lee, D.O.San Mateo, CA 944021326589581
- John Siebel, M.D.San Mateo, CA 944021780741306
- Casey Bermack, MD PHDFoster City, CA 944041588125199
- Ann Lowe, M.D.Palo Alto, CA 943061013278811
- Pamela Basto, MD, PHDStanford, CA 943051194221903
- James Dickerson, MDStanford, CA 943051851897813
- Timothy Ellis-Caleo, MDStanford, CA 943051891258737
- Jordan Goldstein, MDStanford, CA 943051295231603
Common questions
What is Ryan Chang's NPI number?
Ryan Chang's National Provider Identifier (NPI) is 1164985263, issued on Apr 8, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Ryan Chang located?
The NPPES record lists a practice address at 218 DE Anza Blvd, San Mateo, CA, 94402. Phone: (415) 514-7520. Providers update this record themselves, so call before visiting.
How can I verify Ryan Chang's license?
NPPES lists California license number A179941, 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 Ryan Chang prescribe under Medicare Part D?
In 2024, Ryan Chang had 50 Medicare Part D claims for 12 beneficiaries; the average among medical oncology physician prescribers was 703. 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.