NPI Portal NPI Lookup & Verification

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Amber Ann Retzlaff, M.D.

Radiation Oncology Physician in Minneapolis, MN · enumerated 2016 · practices at Allina Health System.

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

National Provider Identifier

1679935860

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Registry record

Entity type Individual (Type 1)
Name Amber Ann Retzlaff
Credential M.D.
Sex Female
Practice address 800 E 28th St Ste 401, Minneapolis, MN, 55407
Phone (612) 863-0200
Enumeration date Mar 25, 2016
Last updated in NPPES Jan 22, 2024

Taxonomy & licenses

2085R0001X Radiation Oncology Physician Allopathic & Osteopathic Physicians · License 71718 (MN) Primary
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.

Read the full guide → Validate an NPI →

Frequently asked questions

What specialty is Amber Retzlaff?
Amber Retzlaff is registered in NPPES with the primary taxonomy of Radiation Oncology 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 2024-01-22.