NPI Portal NPI Lookup & Verification

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

Dr. Warwick Douglas Johnston III, ND

Naturopath in Tustin, CA · enumerated 2018 · practices at Rita R Ellithorpe MD, Inc.

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

National Provider Identifier

1932617388

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)
Name Dr. Warwick Douglas Johnston III
Credential ND
Sex Male
Practice address Tustin, CA, 92780
Phone (714) 544-1521
Enumeration date Jan 19, 2018
Last updated in NPPES Oct 25, 2022

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

Taxonomy & licenses

175F00000X Naturopath Other Service Providers · License ND-289 (HI) Secondary
175F00000X Naturopath Other Service Providers · License ND1350 (CA) Primary

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

How do I verify Warwick Johnston's NPI record?
Cross-check NPI 1932617388 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.
Is NPI 1932617388 active?
Yes, as of the latest NPPES snapshot, NPI 1932617388 is active (record last updated 2022-10-25).

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2022-10-25.