Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. John T Duffin, PHD

Psychologist in Watertown, WI · enumerated 2005.

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

National Provider Identifier

1932184868

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Registry record

Entity type Individual (Type 1)

Name Dr. John T Duffin

Credential PHD

Sex Male

Practice address 129 Hospital Dr, Watertown, WI, 53098

Phone (920) 262-4800

Fax (920) 262-4813

Enumeration date Dec 14, 2005

Last updated in NPPES Jul 8, 2007

Taxonomy & licenses

103T00000X Psychologist Behavioral Health & Social Service Providers · License 871057 (WI) Primary

PHD · Doctor of Philosophy: A doctoral degree; in healthcare often held by clinical psychologists and researchers. About the PHD credential

Other identifiers

Identifier	Type	State	Issuer
3909110	Medicaid	WI	-

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

How do I verify John Duffin's NPI record?

Cross-check NPI 1932184868 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

Is NPI 1932184868 active?

Yes, as of the latest NPPES snapshot, NPI 1932184868 is active (record last updated 2007-07-08).

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.