Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Ben Williams Sonnichsen, MD

Family Medicine Physician in Prosser, WA · enumerated 2006.

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

National Provider Identifier

1295841914

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Registry record

Entity type Individual (Type 1)

Name Dr. Ben Williams Sonnichsen

Credential MD

Sex Male

Practice address 820 Memorial Street, Suite 1, Prosser, WA, 99350

Phone (509) 786-2010

Fax (509) 788-1794

Enumeration date Aug 23, 2006

Last updated in NPPES Dec 5, 2011

Taxonomy & licenses

207Q00000X Family Medicine Physician Allopathic & Osteopathic Physicians · License MD00017164 (WA) Secondary

207Q00000X Family Medicine Physician Allopathic & Osteopathic Physicians · License MD00029197 (WA) 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
1585801	Medicaid	WA	-
9392SO	Other	WA	REGENCE
911019392	Other	-	COMMERCIAL
0200685	Other	WA	L & I
1306897681	Other	-	NPI PROSSER MEMORIAL
1585801	Other	WA	CHPW

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 Ben Sonnichsen?

Ben Sonnichsen is registered in NPPES with the primary taxonomy of Family Medicine 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

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Thomas Halvorson Orthopaedic Surgery Physician · Prosser, WA NPI 1578555264

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-12-05.