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

Stefan Eric Lowenstein, MD

Dermatology Physician in Mill Valley, CA · enumerated 2018.

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

National Provider Identifier

1245728807

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Registry record

Entity type Individual (Type 1)
Name Stefan Eric Lowenstein
Credential MD
Sex Male
Practice address Mill Valley, CA, 94941
Phone (415) 383-5475
Fax (415) 383-1275
Enumeration date Apr 28, 2018
Last updated in NPPES Apr 23, 2026

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

Taxonomy & licenses

207N00000X Dermatology Physician Allopathic & Osteopathic Physicians · License A165056 (CA) Primary
390200000X Student in an Organized Health Care Education/Training Program Student, Health Care Secondary
207ZD0900X Dermatopathology (Pathology) Physician Allopathic & Osteopathic Physicians · License A165056 (CA) Secondary
207ND0101X MOHS-Micrographic Surgery Physician Allopathic & Osteopathic Physicians · License A165056 (CA) Secondary
MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

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

Where does Stefan Lowenstein practice?
The practice location on file with NPPES is in Mill Valley, CA. Providers can have multiple locations; NPPES lists the primary practice address.
What is the NPI number for Stefan Lowenstein?
The National Provider Identifier (NPI) for Stefan Lowenstein is 1245728807, a Type 1 (individual) record in the CMS NPPES registry.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-04-23.