Timothy Euiwon Byun, MD
Hematology & Oncology Physician · Orange, CA
Timothy Euiwon Byun, MD is a hematology & oncology physician with a practice address in Orange, California, and NPI 1871545012, issued on May 16, 2006. Check the license (California A70195, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Timothy Euiwon Byun
- Credential
- MD
- Primary taxonomy
- Hematology & Oncology Physician 207RH0003X
- License number
- A70195 CA
Self-reported in NPPES; status is on the state search - Practice location
- 805 W LA Veta Ave Ste 101, Orange, CA 92868
- Phone
- (714) 835-1800
- Enumerated
- May 16, 2006
- Record last updated
- Jun 4, 2024
- Medicaid ID
- 00A701950734 CA
- Medicare enrollment
- Enrolled (PECOS I20040713001680); accepts Medicare assignment
- Medical or professional school
- Rush Medical College Of Rush University, 1998
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest hematology & oncology physician records → All 1,583 in California → Look up another NPI →
Also registered at 805 W LA Veta Ave Ste 101
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Jacadi Bignami, M.D.Obstetrics & Gynecology Physician1780023804
- Nichole Dang, PAPhysician Assistant1376093088
- Amber Lewis, NPFamily Nurse Practitioner1689231995
- Madhavi Mummaneni, MDHematology & Oncology Physician1316999550
- Patti Pickler, NPFamily Nurse Practitioner1275018210
- Sarah Rand, MSN, WHNP-BCWomen's Health Nurse Practitioner1871972539
Verify Timothy Euiwon Byun in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A70195Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
82% more Medicare Part D claims than the average hematology & oncology physician in 2024
1,599 Medicare Part D claims for 282 beneficiaries, against an average of 877 among the 10,784 providers of this specialty who prescribed in Part D. Brand-name drugs were 31% of claims. 25 claims were for opioids.
Most prescribed
- Anastrozole109 claims
- Xtandi98 claims
- Eliquis70 claims
- Prednisone66 claims
- Dexamethasone63 claims
- Hydroxyurea59 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: $6,725.86
235 payments; by number, the most common kind was food and beverage; the largest payer was AstraZeneca Pharmaceuticals LP. The 8,560 providers of this specialty with any payment received $7,481.41 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
- Providence Medical FoundationOrange, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Timothy Euiwon Byun among 1,583 hematology & oncology physician records in California
Timothy Euiwon Byun, MD is one of 1,583 hematology & oncology 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 2006, is newer than 8% of them.
- NPI issued2006 · 8% of these records are older, 54% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 71% of these records are
- Graduated1998 · median 2003 among the 1,124 with a school on file
- Record last updated2024 · 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 207RH0003X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Hematology & Oncology Physician providers in California
There are 1,583 hematology & oncology physician records in California.
All 1,583 in California → Every provider in Orange → Hematology & Oncology Physician nationwide →
The 8 hematology & oncology physician records with the nearest ZIP codes
- Warren Chow, MDOrange, CA 928681093822017
- Paul Coluzzi, M.D.Orange, CA 928681972563906
- Mihaela Cristea, MDOrange, CA 928681417050998
- Sam Huang, M.D.Orange, CA 928681841248812
- Tiberio Lindgren, MDOrange, CA 928681275585424
- John Link, MDOrange, CA 928681245281211
- Steven Lipkin, MDOrange, CA 928681134153547
- Tariq Mahmood, M.D.Orange, CA 928681104874171
Common questions
What is Timothy Euiwon Byun, MD's NPI number?
Timothy Euiwon Byun, MD's National Provider Identifier (NPI) is 1871545012, issued on May 16, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Timothy Euiwon Byun, MD located?
The NPPES record lists a practice address at 805 W LA Veta Ave Ste 101, Orange, CA, 92868. Phone: (714) 835-1800. Providers update this record themselves, so call before visiting.
How can I verify Timothy Euiwon Byun, MD's license?
NPPES lists California license number A70195, 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 Timothy Euiwon Byun, MD prescribe under Medicare Part D?
In 2024, Timothy Euiwon Byun, MD had 1,599 Medicare Part D claims for 282 beneficiaries; the average among hematology & oncology physician prescribers was 877. 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.