Susan M. O'Brien, M.D.
Medical Oncology Physician · Orange, CA
Susan M. O'Brien, M.D. is a medical oncology physician with a practice address in Orange, California, and NPI 1669577276, issued on Sep 14, 2006. Check the license on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Susan M. O'Brien
- Credential
- M.D.
- Primary taxonomy
- Medical Oncology Physician 207RX0202X
- License number
- H3130 TX
Self-reported in NPPES; status is on the state search - Practice location
- 101 The City Drive South, Orange, CA 92868
- Phone
- (714) 456-8000
- Enumerated
- Sep 14, 2006
- Record last updated
- Jun 6, 2019 (not updated in 7 years: call before relying on the address or phone)
- Fax
- (714) 456-3810
- Medicaid ID
- 100519101 TX
- Medicare enrollment
- Enrolled (PECOS I20150615002538); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest medical oncology physician records → All 447 in California → Look up another NPI →
Also registered at 101 The City Drive South
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Nicholas Ambus, MDStudent in an Organized Health Care Education/Training Program1245084649
- Elham AmiriStudent in an Organized Health Care Education/Training Program1497160972
- Kellie Binder, NPPain Management Registered Nurse1114179611
- Robert Bristow, MDGynecologic Oncology Physician1427016039
- Madison CarterStudent in an Organized Health Care Education/Training Program1306692199
- Metha Chea, MDStudent in an Organized Health Care Education/Training Program1164363420
Verify Susan M. O'Brien in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of CaliforniaCheck the board
- 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
74% fewer Medicare Part D claims than the average medical oncology physician in 2024
180 Medicare Part D claims for 25 beneficiaries, against an average of 703 among the 4,230 providers of this specialty who prescribed in Part D. Brand-name drugs were 79% of claims.
Most prescribed
- Imbruvica48 claims
- Calquence45 claims
- Venclexta18 claims
- Bosulif15 claims
- Restasis Multidose12 claims
- Latanoprost11 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): 100 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: $44,387.45
42 payments; by number, the most common kind was consulting fee; the largest payer was Abbvie 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.
Bills Medicare through one group practice
- UC RegentsOrange, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Susan M. O'Brien among 447 medical oncology physician records in California
Susan M. O'Brien, M.D. 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 2006, is newer than 6% of them.
- NPI issued2006 · 6% of these records are older, 55% newer
- In a Medicare fileYes · 82% of these records are
- In the CMS Doctors and Clinicians fileYes · 70% of these records are
- Graduated1980 · median 2004 among the 312 with a school on file
- Record last updated2019 · 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 Orange → Medical Oncology Physician nationwide →
The 8 medical oncology physician records with the nearest ZIP codes
- Farshid Dayyani, M.D., PH.D.Orange, CA 928681376710434
- Samuel Ejadi, MDOrange, CA 928681285605212
- Sayeh Lavasani, MDOrange, CA 928681205130572
- Jennifer Valerin, M.D.Orange, CA 928681376770255
- Victoria Villaflor, M.D.Orange, CA 928681154380582
- Richard Lloyd, M.D.Fullerton, CA 928351073509030
- David Park, M.D.Fullerton, CA 928351275619447
- Giribala Patel, M.D.Fullerton, CA 928351033106562
Common questions
What is Susan M. O'Brien, M.D.'s NPI number?
Susan M. O'Brien, M.D.'s National Provider Identifier (NPI) is 1669577276, issued on Sep 14, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Susan M. O'Brien, M.D. located?
The NPPES record lists a practice address at 101 The City Drive South, Orange, CA, 92868. Phone: (714) 456-8000. Providers update this record themselves, so call before visiting.
How can I verify Susan M. O'Brien, M.D.'s license?
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 Susan M. O'Brien, M.D. prescribe under Medicare Part D?
In 2024, Susan M. O'Brien, M.D. had 180 Medicare Part D claims for 25 beneficiaries; the average among medical oncology physician prescribers was 703. Part D covers Medicare prescriptions only.
What is Susan M. O'Brien, M.D.'s MIPS final score?
The 2023 MIPS final score is 100 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.