Peter O'Brien, FNP
NPI 1639533490 · Family Nurse Practitioner · Murrieta, CA
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Peter O'Brien, FNP is a Family Nurse Practitioner provider in Murrieta, CA (NPI 1639533490).
Provider details
- NPI number
- 1639533490
- Entity type
- Individual
- Primary specialty
- Family Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- FNP
- Sex
- Male
- Sole proprietor
- No
- License
- 95003926 (CA)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
10 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
191 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. 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 .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 117 | $80 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 52 | $98 |
| Automated Urinalysis Test81003 | 22 | $2 |
Typical Medicare-allowed amounts for these services range $2–$98 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 13 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Azithromycin | 61 | 61 |
| Prednisone | 33 | 32 |
| Methylprednisolone | 30 | 30 |
| Nitrofurantoin Monohyd/M-Crystbrand: Nitrofurantoin Mono-Macro | 28 | 26 |
| Amoxicillin/Potassium Clavbrand: Amoxicillin-Clavulanate Potass | 28 | 28 |
| Albuterol Sulfatebrand: Albuterol Sulfate Hfa | 27 | 26 |
| Mupirocin |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$31 across 1 record (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
Registry dates
- Enumerated
- 2016-04-07
- Last updated
- 2020-03-10
- Certified
- 2020-03-10
Frequently asked questions
- What is Peter O'Brien's NPI number?
- Peter O'Brien's National Provider Identifier (NPI) is 1639533490, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Peter O'Brien's specialty?
- Peter O'Brien is listed in the NPPES registry with a primary specialty of Family Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Peter O'Brien located?
- Peter O'Brien's practice location on file with NPPES is 41880 Kalmia St Ste 100, Murrieta, CA 92562-8835.
- What is Peter O'Brien's phone number?
- The practice phone number listed in the NPPES registry for Peter O'Brien is (951) 397-4226.
- Does Peter O'Brien accept Medicare?
- Peter 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 Peter O'Brien's NPI active?
- Yes — Peter O'Brien's NPI (1639533490) is active in the NPPES registry as of the last update on 2020-03-10.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.