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

Matthew Werner Muellenhoff, D.O.

Procedural Dermatology Physician in Grass Valley, CA · enumerated 2005 · practices at Sierra Derm Inc..

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

National Provider Identifier

1740280650

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Registry record

Entity type Individual (Type 1)
Name Matthew Werner Muellenhoff
Credential D.O.
Sex Male
Practice address Grass Valley, CA, 95945
Phone (530) 272-2303
Fax (530) 272-9648
Enumeration date Jul 21, 2005
Last updated in NPPES Apr 8, 2013

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

Taxonomy & licenses

207NS0135X Procedural Dermatology Physician Allopathic & Osteopathic Physicians · License 20A7904 (CA) Primary
207N00000X Dermatology Physician Allopathic & Osteopathic Physicians · License 20A7904 (CA) Secondary
DO · Doctor of Osteopathic Medicine: A fully licensed physician trained in osteopathic medical schools, with the same practice rights as an MD. About the DO 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

What specialty is Matthew Muellenhoff?
Matthew Muellenhoff is registered in NPPES with the primary taxonomy of Procedural Dermatology Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.
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.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2013-04-08.