Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Alexander George Chamessian, MD PHD

Physical Medicine & Rehabilitation Physician in Creve Coeur, MO · enumerated 2019 · practices at Washington University.

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

National Provider Identifier

1275194839

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Registry record

Entity type Individual (Type 1)

Name Dr. Alexander George Chamessian

Credential MD PHD

Sex Male

Practice address 1044 N Mason Rd, Dept Anesthesiology, Ste L30, Creve Coeur, MO, 63141

Phone (314) 996-8631

Fax (314) 996-8742

Enumeration date Jun 25, 2019

Last updated in NPPES Nov 21, 2025

Taxonomy & licenses

2081P2900X Pain Medicine (Physical Medicine & Rehabilitation) Physician Allopathic & Osteopathic Physicians · License 2023022542 (MO) Secondary

208100000X Physical Medicine & Rehabilitation Physician Allopathic & Osteopathic Physicians · License 2023022542 (MO) Primary

207LP2900X Pain Medicine (Anesthesiology) Physician Allopathic & Osteopathic Physicians · License 2023022542 (MO) Secondary

Other identifiers

Identifier	Type	State	Issuer
200072045	Medicaid	MO	-

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 Alexander Chamessian?

Alexander Chamessian is registered in NPPES with the primary taxonomy of Physical Medicine & Rehabilitation Physician. 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 2025-11-21.