NPI Portal NPI Lookup & Verification

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

Dr. William M Sonak, D.C.

Chiropractor in Sterling, VA · enumerated 2006.

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

National Provider Identifier

1336179183

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Registry record

Entity type Individual (Type 1)
Name Dr. William M Sonak
Credential D.C.
Sex Male
Practice address Sterling, VA, 20164
Enumeration date Jul 4, 2006
Last updated in NPPES Jul 8, 2007

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

Taxonomy & licenses

111N00000X Chiropractor Chiropractic Providers · License 0104555566 (VA) Primary
DC — Doctor of Chiropractic: A licensed chiropractor focusing on musculoskeletal and nervous system disorders. About the DC 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

Where does William Sonak practice?
The practice location on file with NPPES is in Sterling, VA. Providers can have multiple locations; NPPES lists the primary practice address.
What is the NPI number for William Sonak?
The National Provider Identifier (NPI) for William Sonak is 1336179183, a Type 1 (individual) record in the CMS NPPES registry.

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2007-07-08.