Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. Mark H Gregory, MD

Q: What is the NPI number for Mark Gregory?

The National Provider Identifier (NPI) for Mark Gregory is 1104843663, a Type 1 (individual) record in the CMS NPPES registry.

Internal Medicine Physician in Saint Louis, MO · enumerated 2006.

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

National Provider Identifier

1104843663

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Registry record

Entity type Individual (Type 1)

Name Dr. Mark H Gregory

Credential MD

Sex Male

Practice address 555 N New Ballas Rd, Suite 110, Saint Louis, MO, 63141

Phone (314) 872-8470

Fax (314) 872-8472

Enumeration date Jul 17, 2006

Last updated in NPPES Jul 9, 2026

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 100578 (MO) 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
920674500	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.

Read the full guide → Validate an NPI →

Frequently asked questions

Where does Mark Gregory practice?

The practice location on file with NPPES is in Saint Louis, MO. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for Mark Gregory?

The National Provider Identifier (NPI) for Mark Gregory is 1104843663, a Type 1 (individual) record in the CMS NPPES registry.

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2026-07-09.