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

Dr. William Joseph Harper, M.D.

Surgery Physician in Helena, MT · enumerated 2007.

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

National Provider Identifier

1366574006

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Registry record

Entity type Individual (Type 1)

Name Dr. William Joseph Harper

Credential M.D.

Sex Male

Practice address Helena, MT, 59601

Phone (406) 442-0099

Fax (406) 442-0208

Enumeration date Mar 9, 2007

Last updated in NPPES Jan 10, 2008

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

Taxonomy & licenses

208600000X Surgery Physician Allopathic & Osteopathic Physicians · License 6273 (MT) Primary

2086S0129X Vascular Surgery Physician Allopathic & Osteopathic Physicians · License 6273 (MT) Secondary

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

Other identifiers

Identifier	Type	State	Issuer
095990	Other	MT	BLUE CROSS BLUE SHIELD MT
0077337	Medicaid	MT	-

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

What is the NPI number for William Harper?

The National Provider Identifier (NPI) for William Harper is 1366574006, a Type 1 (individual) record in the CMS NPPES registry.

Where does William Harper practice?

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

Other providers at this practice address

Browse all →

Natalie Gonzales Surgery Physician · Helena, MT NPI 1144374786 William J Harper MD PC Surgery Physician · Helena, MT NPI 1386829216 Natalie Gonzales Do PC Surgery Physician · Helena, MT NPI 1467637397 Jason Smith Foot & Ankle Surgery Podiatrist · Helena, MT NPI 1063701431 St Peter'S Medical Group Surgery Physician · Helena, MT NPI 1346680865 Elkhorn Foot and Ankle Pllc Podiatric Clinic/Center · Helena, MT NPI 1932563939

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2008-01-10.