Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum Sole proprietor
Dr. William H Langfield Jr.
Optometrist in Somerset, MA · enumerated 2006.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1477645521
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Registry record
Street address withheld: NPPES sole-proprietor addresses can be home addresses. See our data policy.
Taxonomy & licenses
Other identifiers
| Identifier | Type | State | Issuer |
|---|---|---|---|
| 24380 | Other | - | BMC HEALTHNET |
| W15566 | Other | MA | BLUE CROSS MA |
| 15227 | Other | MA | HARVARD PILGRIM |
| 79024 | Other | - | BLUE CROSS RI |
| 0344214 | Medicaid | MA | - |
| 2201002 | Other | MA | UNITED HEALTH |
| 400875 | Other | - | BLUECHIP |
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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Other providers at this practice address
Browse all →Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2009-02-20.