Gail O'Brien, MD
NPI 1548236466 · Internal Medicine Physician · Boston, MA
Enrolled with Medicare as Practitioner - Internal Medicine · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gail O'Brien, MD is a Internal Medicine Physician provider in Boston, MA (NPI 1548236466).
Provider details
- NPI number
- 1548236466
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- No
- License
- 224147 (MA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 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
174 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) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 142 | $135 |
| Established Patient Office Or Other Outpatient Visit With High Level of Medical Decision Making, If Using Time, 40 Minutes Or More99215 | 17 | $185 |
| New Patient Office Or Other Outpatient Visit With a High Level of Medical Decision Making, If Using Time, 60 Minutes Or More99205 | 15 | $239 |
Typical Medicare-allowed amounts for these services range $135–$239 (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 · 7 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Semaglutidebrand: Ozempic | 100 | 22 |
| Metformin Hcl | 63 | 29 |
| Topiramate | 45 | 13 |
| Semaglutidebrand: Wegovy | 32 | 11 |
| Dulaglutidebrand: Trulicity | 21 | — |
| Tirzepatidebrand: Mounjaro | 20 | — |
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-02-28
- Last updated
- 2021-11-11
- Certified
- 2021-11-11
Frequently asked questions
- What is Gail O'Brien's NPI number?
- Gail O'Brien's National Provider Identifier (NPI) is 1548236466, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gail O'Brien's specialty?
- Gail O'Brien is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Gail O'Brien located?
- Gail O'Brien's practice location on file with NPPES is 55 Fruit St, Boston, MA 02114-2621.
- What is Gail O'Brien's phone number?
- The practice phone number listed in the NPPES registry for Gail O'Brien is (617) 724-4260.
- Does Gail O'Brien accept Medicare?
- Gail 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 Gail O'Brien's NPI active?
- Yes — Gail O'Brien's NPI (1548236466) is active in the NPPES registry as of the last update on 2021-11-11.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.