Leonard A. Farber, M.D.
Radiation Oncology Physician · Fullerton, CA
Leonard A. Farber, M.D. is a radiation oncology physician with a practice address in Fullerton, California, and NPI 1639185838, issued on Jul 31, 2006. Check the license (California C153081, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Leonard A. Farber
- Credential
- M.D.
- Primary taxonomy
- Radiation Oncology Physician 2085R0001X
- License numbers
- C153081 CA
210306 NY
Self-reported in NPPES; status is on the state search - Practice location
- 2151 N Harbor Blvd Ste 1500, Fullerton, CA 92835
- Phone
- (714) 446-5632
- Enumerated
- Jul 31, 2006
- Record last updated
- Apr 10, 2018 (not updated in 8 years: call before relying on the address or phone)
- Entity
- Type 1 · individual
8 nearest radiation oncology physician records → All 735 in California → Look up another NPI →
Also registered at 2151 N Harbor Blvd Ste 1500
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Young Lee, M.D.Radiation Oncology Physician1710986260
- Tommy Sheu, MDRadiation Oncology Physician1568880060
Verify Leonard A. Farber in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license C153081Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Industry payments in 2024: $44.41
1 payment: food and beverage; the largest payer was Siemens Medical Solutions USA, Inc. The 3,275 providers of this specialty with any payment received $1,897.85 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.
Leonard A. Farber among 735 radiation oncology physician records in California
Leonard A. Farber, M.D. is one of 735 radiation 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 16% of them.
- NPI issued2006 · 16% of these records are older, 55% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileNo · 74% of these records are
- Record last updated2018 · 55% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 2085R0001X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Radiation Oncology Physician providers in California
There are 735 radiation oncology physician records in California.
All 735 in California → Every provider in Fullerton → Radiation Oncology Physician nationwide →
The 8 radiation oncology physician records with the nearest ZIP codes
- Dechen Dolkar, MDFullerton, CA 928351861475683
- Young Lee, M.D.Fullerton, CA 928351710986260
- Tommy Sheu, MDFullerton, CA 928351568880060
- Robert Ash, MDOrange, CA 928681326238650
- Tanuja Bhandari, MDOrange, CA 928681518147610
- Allen Chen, M.D.Orange, CA 928681518992981
- Megan Daly, M.D.Orange, CA 928681780863340
- Steven Davis, M.D.Orange, CA 928681558463653
Common questions
What is Leonard A. Farber, M.D.'s NPI number?
Leonard A. Farber, M.D.'s National Provider Identifier (NPI) is 1639185838, issued on Jul 31, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Leonard A. Farber, M.D. located?
The NPPES record lists a practice address at 2151 N Harbor Blvd Ste 1500, Fullerton, CA, 92835. Phone: (714) 446-5632. Providers update this record themselves, so call before visiting.
How can I verify Leonard A. Farber, M.D.'s license?
NPPES lists California license number C153081, 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.
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.