Type 2 · Organization ✓ Active NPI ✓ Valid NPI checksum

Robert J Obrien Jr, MD and Associates PC

Q: What is the NPI number for Robert J Obrien Jr, MD and Associates PC?

The NPI for Robert J Obrien Jr, MD and Associates PC is 1033563960, a Type 2 (organization) record in the CMS NPPES registry.

Specialist in Winchester, MA · enumerated 2016 · authorized official Donna O'Brien, Office Manager.

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

National Provider Identifier

1033563960

Verified

See something wrong? Report a correction

Registry record

Entity type Organization (Type 2)

Legal business name Robert J Obrien Jr, MD and Associates PC

Practice address 955 Main St, Suite G6, Winchester, MA, 01890

Phone (781) 729-4878

Enumeration date Apr 18, 2016

Last updated in NPPES Apr 18, 2016

Taxonomy & classification

174400000X Specialist Other Service Providers Primary

Authorized official

Name Donna O'Brien

Title Office Manager

Phone (781) 729-4878

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 is the NPI number for Robert J Obrien Jr, MD and Associates PC?

The NPI for Robert J Obrien Jr, MD and Associates PC is 1033563960, a Type 2 (organization) record in the CMS NPPES registry.

Who is the authorized official for Robert J Obrien Jr, MD and Associates PC?

NPPES lists Donna O'Brien (Office Manager) as the authorized official for this organization.

Providers at this address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2016-04-18.