Mark O'Connor, M.D.
NPI 1215297270 · Cardiovascular Disease Physician · Leominster, MA
Enrolled with Medicare as Practitioner - Cardiovascular Disease (cardiology) · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark O'Connor, M.D. is a Cardiovascular Disease Physician provider in Leominster, MA (NPI 1215297270).
Provider details
- NPI number
- 1215297270
- Entity type
- Individual
- Primary specialty
- Cardiovascular Disease PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- No
- License
- 277574 (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
14 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
2,983 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) |
|---|---|---|
| Routine Electrocardiogram (ecg) Using at Least 12 Leads With Interpretation and Report93000 | 1,054 | $15 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 681 | $132 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 323 | $94 |
| Ultrasound of Heart With Color-Depicted Blood Flow, Rate, Direction and Valve Function93306 | 224 | $198 |
| Evaluation of Single, Dual, Multiple Lead Or Leadless Pacemaker System Or Implantable Defibrillator System, Remote Up to 90 Days93296 | 159 | $23 |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 42 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Metoprolol Succinate | 788 | 258 |
| Apixabanbrand: Eliquis | 689 | 180 |
| Atorvastatin Calcium | 469 | 155 |
| Rosuvastatin Calcium | 401 | 134 |
| Amlodipine Besylate | 263 | 89 |
| Lisinopril | 250 | 89 |
| Furosemide |
Practice location
Mailing address
Registry dates
- Enumerated
- 2012-05-24
- Last updated
- 2025-09-10
- Certified
- 2025-09-10
Frequently asked questions
- What is Mark O'Connor's NPI number?
- Mark O'Connor's National Provider Identifier (NPI) is 1215297270, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark O'Connor's specialty?
- Mark O'Connor is listed in the NPPES registry with a primary specialty of Cardiovascular Disease Physician (Allopathic & Osteopathic Physicians).
- Where is Mark O'Connor located?
- Mark O'Connor's practice location on file with NPPES is 100 Hospital Rd, Leominster, MA 01453-2253.
- What is Mark O'Connor's phone number?
- The practice phone number listed in the NPPES registry for Mark O'Connor is (978) 466-2052.
- Does Mark O'Connor accept Medicare?
- Mark 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 Mark O'Connor's NPI active?
- Yes — Mark O'Connor's NPI (1215297270) is active in the NPPES registry as of the last update on 2025-09-10.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.