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Joan H. Mass, MD

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

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

National Provider Identifier

1295708162

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Registry record

Entity type Individual (Type 1)
Name Joan H. Mass
Credential MD
Sex Female
Practice address 300 1st Capitol Dr, Saint Charles, MO, 63301
Phone (636) 947-5000
Fax (314) 317-0606
Enumeration date Feb 9, 2006
Last updated in NPPES May 4, 2012

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License R9A66 (MO) Primary
208M00000X Hospitalist Physician Allopathic & Osteopathic Physicians · License R9A66 (MO) Secondary
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
1295708162 Medicaid IL -
207941121 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

What is the NPI number for Joan Mass?
The National Provider Identifier (NPI) for Joan Mass is 1295708162, a Type 1 (individual) record in the CMS NPPES registry.
Where does Joan Mass practice?
The practice location on file with NPPES is in Saint Charles, MO. Providers can have multiple locations; NPPES lists the primary practice address.

Other providers at this practice address

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Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2012-05-04.