Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Abner Louissaint Jr., MD, PHD

Anatomic Pathology & Clinical Pathology Physician in Boston, MA · enumerated 2007.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1124154950

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Abner Louissaint Jr.

Credential MD, PHD

Sex Male

Practice address Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114

Phone (617) 726-2967

Enumeration date Feb 26, 2007

Last updated in NPPES May 15, 2026

Taxonomy & licenses

207ZP0102X Anatomic Pathology & Clinical Pathology Physician Allopathic & Osteopathic Physicians · License L-225010 (MA) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

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 → Validate an NPI →

Frequently asked questions

What specialty is Abner Louissaint?

Abner Louissaint is registered in NPPES with the primary taxonomy of Anatomic Pathology & Clinical Pathology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-05-15.