Brian J. Leberthon, M.D.
Hematology & Oncology Physician · West Covina, CA
Brian J. Leberthon, M.D. is a hematology & oncology physician with a practice address in West Covina, California, and NPI 1326023979, issued on Dec 7, 2005. Check the license (California G79934, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Brian J. Leberthon
- Credential
- M.D.
- Primary taxonomy
- Hematology & Oncology Physician 207RH0003X
- License number
- G79934 CA
Self-reported in NPPES; status is on the state search - Practice location
- 1135 S Sunset Ave, West Covina, CA 91790
- Phone
- (626) 338-9560
- Enumerated
- Dec 7, 2005
- Record last updated
- Dec 14, 2016 (not updated in 10 years: call before relying on the address or phone)
- Fax
- (626) 338-9360
- Medicaid IDs
- 1821202060 CA
00G799340 CA - Medicare enrollment
- Enrolled (PECOS I20041213000326); accepts Medicare assignment
- Medical or professional school
- University Of Southern California Keck School Of Medicine, 1993
- Entity
- Type 1 · individual
8 nearest hematology & oncology physician records → All 1,583 in California → Look up another NPI →
Also registered at 1135 S Sunset Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Lindsay Arellano, PA-CMedical Physician Assistant1659623379
- Sartaj Arora, MDGastroenterology Physician1841258340
- Gabriel Bailey, DOStudent in an Organized Health Care Education/Training Program1003660788
- David Bode, M.D.Body Imaging Physician1306895990
- Amitabh Chauhan, M.D.Internal Medicine Physician1619925948
- Mark Curran, M.D.Maternal & Fetal Medicine Physician1306935689
Verify Brian J. Leberthon in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license G79934Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
3.5 times the Medicare Part D claims of the average hematology & oncology physician in 2024
3,059 Medicare Part D claims for 233 beneficiaries, against an average of 877 among the 10,784 providers of this specialty who prescribed in Part D. Brand-name drugs were 23% of claims. 26 claims were for opioids.
Most prescribed
- Pantoprazole Sodium158 claims
- Omeprazole106 claims
- Levothyroxine Sodium89 claims
- Eliquis87 claims
- Amlodipine Besylate78 claims
- Anastrozole76 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.
The MIPS final score for 2023 (Medicare payment program): 92.4 of 100
The Merit-based Incentive Payment System score is reported for this clinician. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $6,010.66
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.
Brian J. Leberthon among 1,583 hematology & oncology physician records in California
Brian J. Leberthon, M.D. 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 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 92% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 71% of these records are
- Graduated1993 · median 2003 among the 1,124 with a school on file
- Record last updated2016 · 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 West Covina → Hematology & Oncology Physician nationwide →
The 8 hematology & oncology physician records with the nearest ZIP codes
- Lydia Chow, M.D.West Covina, CA 917901770087314
- Subhash Dhand, M.D.West Covina, CA 917901497930903
- Michelle El-Hajjaoui, DOWest Covina, CA 917901184010662
- Phyllis Klein, M.D.West Covina, CA 917901932166519
- Cary Presant, M.D.West Covina, CA 917901538109517
- Camille Adeimy, MDUpland, CA 917861477785160
- Mark Chang, DOUpland, CA 917861861954182
- Natasha GargUpland, CA 917861831458835
Common questions
What is Brian J. Leberthon, M.D.'s NPI number?
Brian J. Leberthon, M.D.'s National Provider Identifier (NPI) is 1326023979, issued on Dec 7, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Brian J. Leberthon, M.D. located?
The NPPES record lists a practice address at 1135 S Sunset Ave, West Covina, CA, 91790. Phone: (626) 338-9560. Providers update this record themselves, so call before visiting.
How can I verify Brian J. Leberthon, M.D.'s license?
NPPES lists California license number G79934, 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 Brian J. Leberthon, M.D. prescribe under Medicare Part D?
In 2024, Brian J. Leberthon, M.D. had 3,059 Medicare Part D claims for 233 beneficiaries; the average among hematology & oncology physician prescribers was 877. Part D covers Medicare prescriptions only.
What is Brian J. Leberthon, M.D.'s MIPS final score?
The 2023 MIPS final score is 92.4 of 100. The average among 454,083 clinicians with a measured score was 83.5.
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.