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

Dr. John Thieszen, M.D.

Hospitalist Physician in Billings, MT · enumerated 2006.

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

National Provider Identifier

1285667816

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Registry record

Entity type Individual (Type 1)

Name Dr. John Thieszen

Credential M.D.

Sex Male

Practice address Billings, MT, 59102

Phone (970) 391-0572

Fax (815) 377-2580

Enumeration date Jul 8, 2006

Last updated in NPPES Dec 6, 2010

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

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 47877-020 (WI) Secondary

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 47210 (CO) Secondary

208M00000X Hospitalist Physician Allopathic & Osteopathic Physicians · License 47210 (CO) Primary

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
60427876	Medicaid	CO	-
12435	Other	MT	MT LIC
47210	Other	CO	CO LIC

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 John Thieszen?

The National Provider Identifier (NPI) for John Thieszen is 1285667816, a Type 1 (individual) record in the CMS NPPES registry.

Where does John Thieszen practice?

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

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2010-12-06.