Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. William P Carter III, M.D.

Emergency Medicine Physician in Portsmouth, NH · enumerated 2006.

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

National Provider Identifier

1083795116

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Registry record

Entity type Individual (Type 1)

Name Dr. William P Carter III

Credential M.D.

Sex Male

Practice address 333 Borthwick Ave, Portsmouth, NH, 03801

Phone (603) 436-5110

Enumeration date Oct 17, 2006

Last updated in NPPES Feb 21, 2023

Taxonomy & licenses

207P00000X Emergency Medicine Physician Allopathic & Osteopathic Physicians · License 13946 (NH) 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
30207888	Medicaid	NH	-
110082238A	Medicaid	MA	-
1083795116	Other	NH	ANTHEM BCBS
P00648240	Other	NH	RAILROAD MEDICARE
432976099	Medicaid	ME	-
AA121001	Other	NH	HARVARD

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 William Carter?

William Carter is registered in NPPES with the primary taxonomy of Emergency Medicine 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.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2023-02-21.