Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

William Nieves, MSW,BA,LMSW

Social Worker in Waterbury, CT · enumerated 2006 · practices at Wellmore, Inc..

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

National Provider Identifier

1457420473

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Registry record

Entity type Individual (Type 1)

Name William Nieves

Credential MSW,BA,LMSW

Sex Male

Practice address 141 E Main St, Waterbury, CT, 06702

Phone (203) 574-9000

Fax (203) 574-9006

Enumeration date Nov 6, 2006

Last updated in NPPES Jun 4, 2021

Taxonomy & licenses

104100000X Social Worker Behavioral Health & Social Service Providers · License 000095 (CT) Primary

Other identifiers

Identifier	Type	State	Issuer
NOT ELIGIBLE	Other	CT	MHN MANAGED HEALTH NETWORK
060669107	Other	CT	UBH-CONNECTICARE WELLMORE GRP/FACILITY
NOT ELIGIBLE	Other	CT	MHN TRICARENORTH
PENDING	Other	CT	CIGNA BEHAVIORAL HEALTH
060669017	Other	CT	UNITED BEHAVIORAL HEALTH
060669107	Other	CT	UBH-LIBERTY/FREEDOM OXFORD HLTH WELLMORE GRP/FACILITY
060669107	Other	CT	ANTHEM BCBS OF CT WELLMORE GRP/FACILITY
004040705	Other	CT	HP MEDICAID
060669107	Other	CT	HEALTHYCT WELLMORE GRP/FACILITY
D339210 -WATERBURY	Other	CT	VALUE OPTIONS
PENDING	Other	CT	AETNA BEHAVIORAL HEALTH
060669107	Other	CT	UBH-UNITED HEALTHCARE WELLMORE GRP/FACILITY
13526788	Other	CT	CAQH

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

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 Nieves?

William Nieves is registered in NPPES with the primary taxonomy of Social Worker. The taxonomy code describes the provider's classification and area of specialization for claims and credentialing.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2021-06-04.