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

Dr. William L Olson, OD

Optometrist in Brockton, MA · enumerated 2006.

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

National Provider Identifier

1427029875

Verified

See something wrong? Report a correction

Registry record

Entity type Individual (Type 1)

Name Dr. William L Olson

Credential OD

Sex Male

Practice address Brockton, MA, 02301

Phone (508) 583-1066

Fax (508) 580-1423

Enumeration date Feb 1, 2006

Last updated in NPPES Oct 14, 2011

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

Taxonomy & licenses

152W00000X Optometrist Eye and Vision Services Providers · License 3534 (MA) Primary

OD · Doctor of Optometry: A licensed optometrist providing primary vision care, eye exams, and corrective lenses. About the OD credential

Other identifiers

Identifier	Type	State	Issuer
9150961	Other	-	CIGNA
726114	Other	-	TUFTS
0030905	Other	-	NEIGHBORHOOD HEALTH PLAN
123637	Other	-	AETNA US HEALTH
2201032	Other	-	UNITED HEALTHCARE
W15854	Other	-	BCBS
S020692	Other	-	CHAMPUS
110016369/A	Medicaid	MA	-
1427029875	Other	-	UNICARE
150721	Other	-	HPHC
410041396	Other	-	RAILROAD MEDICARE
MA3534	Other	-	EYE MED VISION CARE

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 William Olson?

William Olson is registered in NPPES with the primary taxonomy of Optometrist. 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 2011-10-14.