Oscar Chen, MD, MS
Ophthalmology Physician · Orange, CA
Oscar Chen, MD, MS is an ophthalmology physician with a practice address in Orange, California, and NPI 1598329989, issued on May 1, 2019. Check the license (California 201127, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Oscar Chen
- Credential
- MD, MS
- Primary taxonomy
- Ophthalmology Physician 207W00000X
- License numbers
- 201127 CA
125077452 IL
Self-reported in NPPES; status is on the state search - Practice location
- 101 The City Dr S, Orange, CA 92868
- Phone
- (949) 824-7105
- Enumerated
- May 1, 2019
- Record last updated
- Jun 4, 2025
- Medicare enrollment
- Enrolled (PECOS I20250606001655); accepts Medicare assignment
- Medical or professional school
- Rush Medical College Of Rush University, 2021
- Entity
- Type 1 · individual
8 nearest ophthalmology physician records → All 2,899 in California → Look up another NPI →
Also registered at 101 The City Dr S
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Danny Abad, PAPhysician Assistant1477158673
- Edward AbaradoStudent in an Organized Health Care Education/Training Program1912855198
- Nagina Abdiani, DOGeriatric Medicine (Family Medicine) Physician1518543271
- Mariam Abdul-Latif, M.D.Pediatrics Physician1538418884
- Eric AbelloOtolaryngology Physician1922566215
- Brandon Abeyta, MDAnesthesiology Physician1841291804
Verify Oscar Chen in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license 201127Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
51% fewer Medicare Part D claims than the average ophthalmology physician in 2024
738 Medicare Part D claims for 217 beneficiaries, against an average of 1,518 among the 16,459 providers of this specialty who prescribed in Part D. Brand-name drugs were 41% of claims.
Most prescribed
- Latanoprost218 claims
- Prednisolone Acetate94 claims
- Brimonidine Tartrate63 claims
- Dorzolamide-Timolol58 claims
- Timolol Maleate56 claims
- Dorzolamide Hcl38 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: $966.75
15 payments; by number, the most common kind was food and beverage; the largest payer was Alcon Vision LLC. The 13,221 providers of this specialty with any payment received $4,535.02 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
- Regents OF The University OF CaliforniaOrange, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Oscar Chen among 2,899 ophthalmology physician records in California
Oscar Chen, MD, MS is one of 2,899 ophthalmology 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 2019, is newer than 92% of them.
- NPI issued2019 · 92% of these records are older, 6% newer
- In a Medicare fileYes · 79% of these records are
- In the CMS Doctors and Clinicians fileYes · 66% of these records are
- Graduated2021 · median 2001 among the 1,907 with a school on file
- Record last updated2025 · 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 207W00000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Ophthalmology Physician providers in California
There are 2,899 ophthalmology physician records in California.
All 2,899 in California → Every provider in Orange → Ophthalmology Physician nationwide →
The 8 ophthalmology physician records with the nearest ZIP codes
- Rahul Bhola, M.D.Orange, CA 928681609910033
- Swaraj Bose, MDOrange, CA 928681285714360
- Michael V Drake, MDOrange, CA 928681356421499
- Babak Fardin, MDOrange, CA 928681174553424
- George Garcia, M.D.Orange, CA 928681437175262
- Laura Howard, M.D.Orange, CA 928681194934109
- Linda Lippa, MDOrange, CA 928681245310499
- Christopher Lyon, PH.D,MDOrange, CA 928681649316753
Common questions
What is Oscar Chen, MD, MS's NPI number?
Oscar Chen, MD, MS's National Provider Identifier (NPI) is 1598329989, issued on May 1, 2019. An NPI identifies a provider in billing; it is not a license.
Where is Oscar Chen, MD, MS located?
The NPPES record lists a practice address at 101 The City Dr S, Orange, CA, 92868. Phone: (949) 824-7105. Providers update this record themselves, so call before visiting.
How can I verify Oscar Chen, MD, MS's license?
NPPES lists California license number 201127, 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 Oscar Chen, MD, MS prescribe under Medicare Part D?
In 2024, Oscar Chen, MD, MS had 738 Medicare Part D claims for 217 beneficiaries; the average among ophthalmology physician prescribers was 1,518. 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.