Daniel O'Brien
Cardiovascular Disease Physician · Rolling Hills Estates, CA
Daniel O'Brien is a cardiovascular disease physician with a practice address in Rolling Hills Estates, California, and NPI 1023512431, issued on Mar 20, 2018. Check the license (California A165839, as entered in NPPES) on the Medical Board of California; the Medicare figures below come from public CMS files.
- Name
- Daniel O'Brien
- Primary taxonomy
- Cardiovascular Disease Physician 207RC0000X
- License number
- A165839 CA
Self-reported in NPPES; status is on the state search - Practice location
- 501 Deep Valley Dr Ste 100, Rolling Hills Estates, CA 90274
- Phone
- (310) 303-3953
- Enumerated
- Mar 20, 2018
- Record last updated
- Mar 25, 2026
- Fax
- (310) 303-7903
- Medicare enrollment
- Enrolled (PECOS I20210519002632); accepts Medicare assignment
- Medical or professional school
- University Of Southern California Keck School Of Medicine, 2018
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest cardiovascular disease physician records → All 2,574 in California → Look up another NPI →
Also registered at 501 Deep Valley Dr Ste 100
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Kimngan NguyenFamily Medicine Physician1902366552
- Robert Reiss, MDInternal Medicine Physician1588746150
Verify Daniel O'Brien in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMedical Board of California
Search for license A165839Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
98% fewer Medicare Part D claims than the average cardiovascular disease physician in 2024
55 Medicare Part D claims for 14 beneficiaries, against an average of 3,078 among the 20,728 providers of this specialty who prescribed in Part D.
Most prescribed
- Atorvastatin Calcium12 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: $482.66
4 payments; by number, the most common kind was food and beverage; the largest payer was Abbott Laboratories. The 16,686 providers of this specialty with any payment received $3,819.56 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
- The Regents OF The University OF CaliforniaSanta Monica, CA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Daniel O'Brien among 2,574 cardiovascular disease physician records in California
Daniel O'Brien is one of 2,574 cardiovascular disease 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 2018, is newer than 93% of them.
- NPI issued2018 · 93% of these records are older, 5% newer
- In a Medicare fileYes · 83% of these records are
- In the CMS Doctors and Clinicians fileYes · 68% of these records are
- Graduated2018 · median 1999 among the 1,742 with a school on file
- Record last updated2026 · 63% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RC0000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Cardiovascular Disease Physician providers in California
There are 2,574 cardiovascular disease physician records in California.
All 2,574 in California → Every provider in Rolling Hills Estates → Cardiovascular Disease Physician nationwide →
The 8 cardiovascular disease physician records with the nearest ZIP codes
- Robert Goldman, M.D.Palos Verdes Estates, CA 902741922332345
- Marvin Appel, M.D.Rancho Palos Verdes, CA 902751891882247
- Bruce Jackson, M.D.Redondo Beach, CA 902771609883438
- Reena Patel, M.D.Redondo Beach, CA 902771639357775
- Cesar Aranguri, M.D.Maywood, CA 902701346297934
- Claudia Tellier, MDMalibu, CA 902651336879360
- Thomas Brodie, M.DLynwood, CA 902621669470142
- Amin Farah, MDLynwood, CA 902621902908080
Common questions
What is Daniel O'Brien's NPI number?
Daniel O'Brien's National Provider Identifier (NPI) is 1023512431, issued on Mar 20, 2018. An NPI identifies a provider in billing; it is not a license.
Where is Daniel O'Brien located?
The NPPES record lists a practice address at 501 Deep Valley Dr Ste 100, Rolling Hills Estates, CA, 90274. Phone: (310) 303-3953. Providers update this record themselves, so call before visiting.
How can I verify Daniel O'Brien's license?
NPPES lists California license number A165839, 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 Daniel O'Brien prescribe under Medicare Part D?
In 2024, Daniel O'Brien had 55 Medicare Part D claims for 14 beneficiaries; the average among cardiovascular disease physician prescribers was 3,078. 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.