Margaret O'Connor, GNP-BC
NPI 1538202452 · Gerontology Nurse Practitioner · Saint Helena, CA
Enrolled with Medicare as Practitioner - Nurse Practitioner · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Margaret O'Connor, GNP-BC is a Gerontology Nurse Practitioner provider in Saint Helena, CA (NPI 1538202452).
Provider details
- NPI number
- 1538202452
- Entity type
- Individual
- Primary specialty
- Gerontology Nurse PractitionerPhysician Assistants & Advanced Practice Nursing Providers
- Credential
- GNP-BC
- Sex
- Female
- Sole proprietor
- No
- License
- 95031336 (CA)
Specialties & taxonomies
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Physician Assistants & Advanced Practice Nursing Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
157 Medicare services, 2024 (ranked within specialty)
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 methodology.
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) |
|---|---|---|
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More99203 | 125 | $93 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 32 | $71 |
Typical Medicare-allowed amounts for these services range $71–$93 (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 · 3 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Donepezil Hcl | 77 | 36 |
| Memantine Hcl | 58 | 27 |
| Sodium, Potassium,mag Sulfatesbrand: Sod Sulf-Potass Sulf-Mag Sulf | 45 | 45 |
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.
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-02-14
- Last updated
- 2026-05-04
- Certified
- 2026-05-04
Frequently asked questions
- What is Margaret O'Connor's NPI number?
- Margaret O'Connor's National Provider Identifier (NPI) is 1538202452, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Margaret O'Connor's specialty?
- Margaret O'Connor is listed in the NPPES registry with a primary specialty of Gerontology Nurse Practitioner (Physician Assistants & Advanced Practice Nursing Providers).
- Where is Margaret O'Connor located?
- Margaret O'Connor's practice location on file with NPPES is 6 Woodland Rd Ste 101, Saint Helena, CA 94574-9501.
- What is Margaret O'Connor's phone number?
- The practice phone number listed in the NPPES registry for Margaret O'Connor is (707) 963-7028.
- Does Margaret O'Connor accept Medicare?
- Margaret O'Connor is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Margaret O'Connor's NPI active?
- Yes — Margaret O'Connor's NPI (1538202452) is active in the NPPES registry as of the last update on 2026-05-04.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.