Michael O'Neill, M.D.
NPI 1356873319 · Internal Medicine Physician · Fairfield, CT
Enrolled with Medicare as Practitioner - Hospitalist · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Michael O'Neill, M.D. is a Internal Medicine Physician provider in Fairfield, CT (NPI 1356873319).
Provider details
- NPI number
- 1356873319
- Entity type
- Individual
- Primary specialty
- Internal Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 305546 (NY)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
9 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
169 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 | 99 | $137 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 30 | $99 |
| Annual Wellness Visit, Includes a Personalized Prevention Plan of Service (pps), Subsequent VisitG0439 | 23 | $143 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 17 | $181 |
Typical Medicare-allowed amounts for these services range $99–$181 (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 · 31 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Atorvastatin Calcium | 101 | 50 |
| Amlodipine Besylate | 83 | 40 |
| Rosuvastatin Calcium | 61 | 25 |
| Losartan Potassium | 54 | 24 |
| Lisinopril | 52 | 22 |
| Levothyroxine Sodium | 47 | 25 |
| Metformin Hcl |
Practice location
Mailing address
Registry dates
- Enumerated
- 2017-03-29
- Last updated
- 2025-06-25
- Certified
- 2025-06-25
Frequently asked questions
- What is Michael O'Neill's NPI number?
- Michael O'Neill's National Provider Identifier (NPI) is 1356873319, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Michael O'Neill's specialty?
- Michael O'Neill is listed in the NPPES registry with a primary specialty of Internal Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is Michael O'Neill located?
- Michael O'Neill's practice location on file with NPPES is 111 Beach Rd, Fairfield, CT 06824-6668.
- What is Michael O'Neill's phone number?
- The practice phone number listed in the NPPES registry for Michael O'Neill is (203) 696-3560.
- Does Michael O'Neill accept Medicare?
- Michael O'Neill is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Michael O'Neill's NPI active?
- Yes — Michael O'Neill's NPI (1356873319) is active in the NPPES registry as of the last update on 2025-06-25.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.