NPI Portal NPI Lookup & Verification

Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor

Mr. Robert Alan Harf, MD FACS

Orthopaedic Surgery of the Spine Physician in Sonoma, CA · enumerated 2006.

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

National Provider Identifier

1023128741

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Registry record

Entity type Individual (Type 1)
Name Mr. Robert Alan Harf
Credential MD FACS
Sex Male
Practice address Sonoma, CA, 95476
Phone (707) 996-8017
Fax (707) 996-8061
Enumeration date Aug 30, 2006
Last updated in NPPES Feb 10, 2017

Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.

Taxonomy & licenses

207XS0117X Orthopaedic Surgery of the Spine Physician Allopathic & Osteopathic Physicians · License A406260 (CA) Primary
207X00000X Orthopaedic Surgery Physician Allopathic & Osteopathic Physicians · License A40626 (CA) Secondary

Other identifiers

Identifier Type State Issuer
P00003535 Other - RAIL ROAD MEDICARE
00A406260 Medicaid CA -

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.

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Frequently asked questions

Where does Robert Harf practice?
The practice location on file with NPPES is in Sonoma, CA. Providers can have multiple locations; NPPES lists the primary practice address.
What is the NPI number for Robert Harf?
The National Provider Identifier (NPI) for Robert Harf is 1023128741, a Type 1 (individual) record in the CMS NPPES registry.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2017-02-10.