Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Gregory T Williams, MD

Infectious Disease Physician in Worcester, MA · enumerated 2006.

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

National Provider Identifier

1043288848

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Registry record

Entity type Individual (Type 1)

Name Gregory T Williams

Credential MD

Sex Male

Practice address 123 Summer Street, Suite 220 S, Worcester, MA, 01608

Phone (508) 368-3122

Fax (508) 368-3121

Enumeration date Mar 9, 2006

Last updated in NPPES Mar 4, 2009

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 79617 (MA) Secondary

207RI0200X Infectious Disease Physician Allopathic & Osteopathic Physicians · License 79617 (MA) 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
AA2844	Other	-	HARVARD PILGRIM HEALTHCAR
J14908	Other	-	BLUE SHIELD IDEMNITY
J14908	Other	-	BLUE SHIELD HMO BLUE
042472266	Other	-	HEALTHCARE VALUE MANAGEME
3130711	Medicaid	MA	-
784106	Other	-	MVP HEALTH CARE
042472266	Other	-	PRIVATE HEALTHCARE SYSTEM
1061518	Other	-	FIRST HEALTH
26881	Other	-	HEALTHY START
042472266	Other	-	ONE HEALTH PLAN
J14908	Other	-	BLUE CARE ELECT
26881	Other	-	CHILDRENS MEDICAL SECURIT
5218590	Other	-	CIGNA HEALTH PLAN
91119	Other	-	FALLON COMMUNITY HEALTH P
5237703	Other	-	AETNA US HEALTHCARE
9200061	Other	-	EVERCARE

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 Gregory Williams?

Gregory Williams is registered in NPPES with the primary taxonomy of Infectious Disease 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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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2009-03-04.