Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Dr. Mary C O'Brien, MD

Individual provider Internal Medicine Physician · NPI 1912980434

Dr. Mary C O'Brien, MD is an Internal Medicine in Shrewsbury, Massachusetts. Graduated from State University of New York at Stony Brook, School of Medicine in 1991, 35 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
35
Trained at
State University of New York at Stony Brook, School of Medicine
Licensed in
MA
In the registry since
2005
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

604 Main St
Shrewsbury, MA 01545-5663
Phone: (508) 842-0057
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 79570 (MA)

Record details

NPI number1912980434
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorNo
NPI enumeratedNovember 29, 2005
Last updated in NPPESNovember 25, 2020
Certification dateNovember 25, 2020

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyINTERNAL MEDICINE
Medical schoolSTATE UNIVERSITY OF NEW YORK AT STONY BROOK, SCHOOL OF MEDICINE
Graduated 1991 (35 years in practice)
Group practice Umass Memorial Medical Group Inc — 2467 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services

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