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

Dr. Karolina Stack, M.D.

Pediatrics Physician in Oshkosh, WI · enumerated 2017.

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

National Provider Identifier

1053842443

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Registry record

Entity type Individual (Type 1)

Name Dr. Karolina Stack

Credential M.D.

Sex Female

Practice address Oshkosh, WI, 54904

Phone (920) 223-8000

Enumeration date Mar 27, 2017

Last updated in NPPES Jun 30, 2025

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

Taxonomy & licenses

208000000X Pediatrics Physician Allopathic & Osteopathic Physicians · License 1053842243 (IL) Secondary

208000000X Pediatrics Physician Allopathic & Osteopathic Physicians · License 036.151998 (IL) Secondary

208000000X Pediatrics Physician Allopathic & Osteopathic Physicians · License 83243 (WI) 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
100273308	Medicaid	WI	-

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

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.

What specialty is Karolina Stack?

Karolina Stack is registered in NPPES with the primary taxonomy of Pediatrics Physician. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-06-30.