Daniel O'Brien
NPI 1023512431 · Cardiovascular Disease Physician · Rolling Hills Estates, CA
Enrolled with Medicare as Practitioner - Cardiovascular Disease (cardiology) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Daniel O'Brien is a Cardiovascular Disease Physician provider in Rolling Hills Estates, CA (NPI 1023512431).
Provider details
- NPI number
- 1023512431
- Entity type
- Individual
- Primary specialty
- Cardiovascular Disease PhysicianAllopathic & Osteopathic Physicians
- Sex
- Male
- Sole proprietor
- Yes
- License
- A165839 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure33% of score
8 yrs in NPPES registry
- Profile completeness33% of score
100% of core fields populated
- Practice footprint20% of score
3 documented practice locations
- Open Payments transparency13% of score
Has Open Payments disclosures (2024)
Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 1 distinct drug on file.
| Drug | Part D claims (2024) |
|---|---|
| Atorvastatin Calcium | 12 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$483 across 4 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (2)
- 200 Ucla Medical Plz Ste 420Los Angeles, CA 90095-8358Phone: (310) 206-6232
- 757 Westwood PlzLos Angeles, CA 90095-8358Phone: (310) 825-9111
Registry dates
- Enumerated
- 2018-03-20
- Last updated
- 2026-03-25
- Certified
- 2026-03-25
Frequently asked questions
- What is Daniel O'Brien's NPI number?
- Daniel O'Brien's National Provider Identifier (NPI) is 1023512431, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Daniel O'Brien's specialty?
- Daniel O'Brien is listed in the NPPES registry with a primary specialty of Cardiovascular Disease Physician (Allopathic & Osteopathic Physicians).
- Where is Daniel O'Brien located?
- Daniel O'Brien's practice location on file with NPPES is 501 Deep Valley Dr Ste 100, Rolling Hills Estates, CA 90274-7606.
- What is Daniel O'Brien's phone number?
- The practice phone number listed in the NPPES registry for Daniel O'Brien is (310) 303-3953.
- Does Daniel O'Brien accept Medicare?
- Daniel O'Brien is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Daniel O'Brien's NPI active?
- Yes — Daniel O'Brien's NPI (1023512431) is active in the NPPES registry as of the last update on 2026-03-25.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.