Mark J. O'Connor, MD
Mark J. O'Connor, MD is a Cardiovascular Disease (Cardiology) in Leominster, Massachusetts. Graduated from University of Massachusetts Medical School in 2012, 14 years ago. Practices with Umass Memorial Medical Group Inc, a 2,467-clinician group, accepts Medicare assignment and offers telehealth. Licensed in Massachusetts.
- Years since qualifying
- 14
- Trained at
- University of Massachusetts Medical School
- Licensed in
- MA
- In the registry since
- 2012
What do these letters mean?
- MD — Doctor of Medicine
- A physician who completed allopathic medical school.
Practice location Address checks out
100 Hospital RdLeominster, MA 01453-2253
Phone: (978) 466-2052
Fax: (978) 466-2085
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Pin is approximate — placed at the ZIP-code centre, not the exact door.
Specialties & licences
| Cardiovascular Disease Physician (primary) | Taxonomy 207RC0000X · Licence 277574 (MA) |
|---|
Record details
| NPI number | 1215297270 |
|---|---|
| Entity type | Individual (Type 1) |
| Gender | Male |
| Credentials | MD |
| Sole proprietor | No |
| NPI enumerated | May 24, 2012 |
| Last updated in NPPES | September 10, 2025 |
| Certification date | September 10, 2025 |
| Mailing address | Po Box 415348, Boston, MA 02241-5348 |
Medicare enrollment
| Medicare specialty | CARDIOVASCULAR DISEASE (CARDIOLOGY) |
|---|---|
| Medical school | UNIVERSITY OF MASSACHUSETTS MEDICAL SCHOOL |
| Graduated | 2012 (14 years in practice) |
| Group practice | Umass Memorial Medical Group Inc — 2467 clinicians |
| Accepts Medicare assignment | Yes — accepts the Medicare-approved amount |
| Telehealth | Offers telehealth services |
| Practice locations | 2 on file with Medicare |
Other providers in Leominster
-
Dr. Ellen M Gallant, MD
60 Hospital Rd, Leominster, MA 01453-2205 · (978) 466-2052
-
Maureen A Maher, MD
100 Hospital Rd 3B Cardiology Internists, Leominster, MA 01453 · (978) 534-3179
-
Paul James McCabe, MD
100 Hospital Rd, Leominster, MA 01453-2253 · (978) 466-2052
-
Dr. Nicholas Michael Mercadante, MD
100 Hospital Rd Ste 3B Professional Bldg, Leominster, MA 01453-2253 · (978) 534-3179
-
Dr. Jonathan Harris Robbins, MD
100 Hospital Rd Ste 3B, Leominster, MA 01453-2253 · (978) 534-3179