Michael J O'Brien, MD
Michael J O'Brien is a Anatomic Pathology Physician provider (Pathology) practicing in Boston, MA, registered in the NPPES registry with NPI 1700858438 since 2006. The credential MD stands for Doctor of Medicine. Practices at Boston University Mallory Pathology Associates, Inc. (listed at the same practice address in NPPES).
✓ Active NPI ✓ Valid NPI checksum
| NPI | 1700858438 |
|---|---|
| Entity type | Individual (Type 1) |
| Name | Michael J O'Brien |
| Credential | MD |
| Sex | Male |
| Practice address | 670 ALBANY ST, FLOOR 3, ROOM 310, Boston, MA, 02118 |
| Phone | 6174145314 |
| Fax | 6174145315 |
| Enumeration date | 2006-02-06 |
| Last updated in NPPES | 2019-10-11 |
Taxonomy & licenses
| Taxonomy code | Specialty | Primary | License | State |
|---|---|---|---|---|
| 207ZP0101X | Anatomic Pathology Physician | Primary | 40684 | MA |
MD — Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential
Other identifiers
| Identifier | Type | State | Issuer |
|---|---|---|---|
| 30204395 | Medicaid | NH | — |
| 6169813 | Medicaid | MA | — |
Copy-ready billing details
Provider: Michael O'Brien, MD NPI: 1700858438 Taxonomy: 207ZP0101X (Anatomic Pathology Physician) Address: 670 ALBANY ST, FLOOR 3, ROOM 310, Boston, MA, 02118
Other providers at this practice address
| NPI | Name | Type | Specialty | Location |
|---|---|---|---|---|
| 1538132923 | Barbarajean Magnani | Individual | Clinical Pathology/Laboratory Medicine Physician | Boston, MA |
| 1306819719 | Sandra Cerda | Individual | Anatomic Pathology & Clinical Pathology Physician | Boston, MA |
| 1114990421 | David Chui | Individual | Hematology (Pathology) Physician | Boston, MA |
| 1184697492 | Antonio De Las Morenas | Individual | Anatomic Pathology & Clinical Pathology Physician | Boston, MA |
| 1144293101 | Dongsheng Xu | Individual | Clinical Pathology/Laboratory Medicine Physician | Boston, MA |
| 1285607226 | Nancy Miller | Individual | Anatomic Pathology & Clinical Pathology Physician | Boston, MA |
| 1457308637 | Boston University Mallory Pathology Associates, Inc. | Organization | Anatomic Pathology & Clinical Pathology Physician | Boston, MA |
| 1265524730 | Brian Moore | Individual | Neuropathology Physician | Boston, MA |
Verify this record
Cross-check NPI 1700858438 against the authoritative CMS record: view Michael J O'Brien on the official NPPES registry .
What is an NPI number?
A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes — even if the provider moves or changes specialty. Read the full guide or validate an NPI number.
Frequently asked questions
What is the NPI number for Michael O'Brien?
Where does Michael O'Brien practice?
Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2019-10-11.