Dr. Gregory Scott Johnston, M.D.

Dr. Gregory Scott Johnston is a General Practice Physician provider (General Practice) practicing in Phoenix, AZ, registered in the NPPES registry with NPI 1447371497 since 2007. The credential MD stands for Doctor of Medicine.

✓ Active NPI ✓ Valid NPI checksum Sole proprietor

NPI	1447371497
Entity type	Individual (Type 1)
Name	Dr. Gregory Scott Johnston
Credential	M.D.
Sex	Male
Practice address	Phoenix, AZ, 85006
Phone	6024700021
Enumeration date	2007-04-03
Last updated in NPPES	2007-07-08

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

Taxonomy & licenses

Taxonomy code	Specialty	Primary	License	State
208D00000X	General Practice Physician	Primary	18453	AZ

MD — Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Copy-ready billing details

Provider: Gregory Johnston, M.D.
NPI: 1447371497
Taxonomy: 208D00000X (General Practice Physician)
Address: Phoenix, AZ, 85006

Other providers at this practice address

NPI	Name	Type	Specialty	Location
1225823271	Cesar Morales	Individual	Medical Physician Assistant	Phoenix, AZ

Verify this record

Cross-check NPI 1447371497 against the authoritative CMS record: view Dr. Gregory Scott Johnston on the official NPPES registry .

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 or validate an NPI number.

Frequently asked questions

Is this the official NPI registry?

No. NPI Portal is a private site built on public CMS NPPES data. The official registry is npiregistry.cms.hhs.gov, operated by CMS.

What specialty is Gregory Johnston?

Gregory Johnston is registered in NPPES with the primary taxonomy of General Practice Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Source: CMS NPPES (public data). Snapshot 2026-07-11. Provider record last updated 2007-07-08.