Karen E. O'Brien, M.D.
Maternal & Fetal Medicine Physician · South Weymouth, MA
Karen E. O'Brien, M.D. is a maternal & fetal medicine physician with a practice address in South Weymouth, Massachusetts, and NPI 1780623215, issued on Jun 6, 2006. Check the license (Massachusetts 218797, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- Karen E. O'Brien
- Credential
- M.D.
- Primary taxonomy
- Maternal & Fetal Medicine Physician 207VM0101X
- License number
- 218797 MA
Self-reported in NPPES; status is on the state search - Practice location
- 55 Fogg RD, South Weymouth, MA 02190
- Phone
- (781) 624-8000
- Enumerated
- Jun 6, 2006
- Record last updated
- Oct 19, 2023
- Medicare enrollment
- Enrolled (PECOS I20040326000773); accepts Medicare assignment
- Medical or professional school
- Georgetown University School Of Medicine, 1996
- Entity
- Type 1 · individual
8 nearest maternal & fetal medicine physician records → All 92 in Massachusetts → Look up another NPI →
Also registered at 55 Fogg RD
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Sarah AmeriDiagnostic Radiology Physician1194347567
- Nita Amornsiripanitch, M.D.Diagnostic Radiology Physician1063791887
- Anjali Andalkar, M.D.Anatomic Pathology & Clinical Pathology Physician1225005234
- Shaheen AndreasPediatric Emergency Medicine (Pediatrics) Physician1407388614
Verify Karen E. O'Brien in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 218797Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
Bills Medicare through one group practice
- South Shore Medical Center, Inc.Weymouth, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Karen E. O'Brien among 92 maternal & fetal medicine physician records in Massachusetts
Karen E. O'Brien, M.D. is one of 92 maternal & fetal medicine physician records with a practice address in Massachusetts. 89% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2006, is newer than 16% of them.
- NPI issued2006 · 16% of these records are older, 54% newer
- In a Medicare fileYes · 89% of these records are
- In the CMS Doctors and Clinicians fileYes · 82% of these records are
- Graduated1996 · median 2005 among the 75 with a school on file
- Record last updated2023 · 41% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207VM0101X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Maternal & Fetal Medicine Physician providers in Massachusetts
There are 92 maternal & fetal medicine physician records in Massachusetts.
All 92 in Massachusetts → Every provider in South Weymouth → Maternal & Fetal Medicine Physician nationwide →
The 8 maternal & fetal medicine physician records with the nearest ZIP codes
- George Graham, MDWeymouth, MA 021901710961859
- Barbara O'Brien, MDWeymouth, MA 021901609915081
- Achilles Athanassiou, M.D.Boston, MA 022151730159419
- Millie Ferres, M.D.Boston, MA 022151568789337
- Kee-Hak Lim, M.D.Boston, MA 022151215919428
- Sarah Little, MDBoston, MA 022151396936415
- Kolawole Oyelese, M.D.Boston, MA 022151568407955
- Deborah Platek, MDBoston, MA 022151760581334
Common questions
What is Karen E. O'Brien, M.D.'s NPI number?
Karen E. O'Brien, M.D.'s National Provider Identifier (NPI) is 1780623215, issued on Jun 6, 2006. An NPI identifies a provider in billing; it is not a license.
Where is Karen E. O'Brien, M.D. located?
The NPPES record lists a practice address at 55 Fogg RD, South Weymouth, MA, 02190. Phone: (781) 624-8000. Providers update this record themselves, so call before visiting.
How can I verify Karen E. O'Brien, M.D.'s license?
NPPES lists Massachusetts license number 218797, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.