Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Robert Elmer Sonnenburg Jr, M.D.

Otolaryngology Physician in Green Bay, WI · enumerated 2005.

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

National Provider Identifier

1972588176

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Robert Elmer Sonnenburg Jr

Credential M.D.

Sex Male

Practice address 2845 Greenbrier Rd, Green Bay, WI, 54311

Phone (920) 288-8230

Fax (920) 288-8235

Enumeration date Dec 9, 2005

Last updated in NPPES May 19, 2026

Taxonomy & licenses

207Y00000X Otolaryngology Physician Allopathic & Osteopathic Physicians · License 47907020 (WI) Primary

207YS0012X Sleep Medicine (Otolaryngology) Physician Allopathic & Osteopathic Physicians · License 47907020 (WI) Secondary

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
34628100	Medicaid	WI	-
4728376	Medicaid	MI	-
4728385	Medicaid	MI	-
4728367	Medicaid	MI	-

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 Robert Sonnenburg Jr?

Robert Sonnenburg Jr is registered in NPPES with the primary taxonomy of Otolaryngology 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.

Other providers at this practice address

Browse all →

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-05-19.