Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Caroline Elizabeth O'Brien, FNP-C

Family Nurse Practitioner in Medford, MA · enumerated 2025.

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

National Provider Identifier

1124828801

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Registry record

Entity type Individual (Type 1)

Name Caroline Elizabeth O'Brien

Credential FNP-C

Sex Female

Practice address 22 Franklin St, Medford, MA, 02155

Phone (781) 350-8571

Enumeration date Mar 13, 2025

Last updated in NPPES Mar 12, 2026

Taxonomy & licenses

363LF0000X Family Nurse Practitioner Physician Assistants & Advanced Practice Nursing Providers · License RN2333758 (MA) Primary

163W00000X Registered Nurse Nursing Service Providers · License RN2333758 (MA) Secondary

163W00000X Registered Nurse Nursing Service Providers · License 093013-21S (NH) Secondary

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

Where does Caroline O'Brien practice?

The practice location on file with NPPES is in Medford, MA. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Caroline O'Brien?

The National Provider Identifier (NPI) for Caroline O'Brien is 1124828801, a Type 1 (individual) record in the CMS NPPES registry.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-03-12.