Gary David Koenig, M.D.
Gastroenterology · Internal Medicine (CMS) · Hazelwood, MO
At a glance
100 Village Sq, Hazelwood, MO 63042-1820
Published activity: Colonoscopy · Upper gastrointestinal (GI) endoscopy for acid reflux. View counts and coverage
NPPES record updated Feb 16, 2026. Public records can lag behind changes at a practice.
Before you call: a quick checklist
- Are you accepting new patients?
- Do you accept my specific insurance plan?
- Do you provide the service I need at this address?
- Do I need a referral, and what is the earliest appointment?
Insurance participation and appointment availability are not established by these public records.
Medicare & insurance
Insurance participation is not established by these public records. Ask the practice and your insurer about your specific plan and this location.
How to check your coverage
Use your plan’s provider directory or the member-services number on your insurance card. Confirm the clinician, practice address, service, and whether a referral is required. A missing opt-out record does not establish Medicare acceptance.
Check the official Medicare directory ↗Practice location
100 Village SqHazelwood, MO 63042-1820
Additional reported practice locations
20 Progress Point Pkwy Ste 206O Fallon, MO 633682207
Phone: 6363441073
Fax: 6369169953
Education & affiliations
- Medical / professional school
- Saint Louis University School Of Medicine
- Graduation year
- 1986
- CMS specialties
- Gastroenterology · Internal Medicine
Practice groups
Reported hospital affiliations
- Barnes-Jewish St Peters Hospital Saint Peters, MO
- Mercy Hospital Washington Washington, MO
- Progress West Hospital Ofallon, MO
Graduation year does not establish years in practice. A reported affiliation does not establish employment, current admitting privileges, or insurance participation.
Source: CMS National Downloadable File · Published Oct 15, 2026.
Source: CMS Facility Affiliation Data · Published Oct 15, 2026.
Procedures in the public data
Reported activity can help you ask more informed questions about a practice’s services.
| Procedure category | Published Medicare activity |
|---|---|
| Colonoscopy | 1-10 |
| Upper gastrointestinal (GI) endoscopy for acid reflux | 15 |
CMS uses a one-year claims window with a reporting lag. Counts cover the Medicare activity included by CMS, not all patients. “1–10” is a published range. Volume is not a quality or outcomes score. Coverage and methodology
Source: CMS Utilization Data · Published Oct 15, 2026.
Find providers with a similar service mix
Compare 2024 published Medicare activity in the same reported specialty, here or in another city.
Industry-reported general payments
Includes reported transfers of value, such as meals, travel, or consulting. Payments do not establish improper conduct or quality of care. Research funding and ownership values are excluded from this total.
See payment purposes and reporting companies
Reported purposes
| Purpose | Amount |
|---|---|
| Food and beverage | $1,528.46 |
| Education | $84.00 |
Reporting companies
| Company | Amount |
|---|---|
| ABBVIE INC. | $436.52 |
| JANSSEN BIOTECH, INC. | $268.54 |
| TAKEDA PHARMACEUTICALS U.S.A., INC. | $170.60 |
| SALIX PHARMACEUTICALS, A DIVISION OF BAUSCH HEALTH US, LLC | $105.66 |
| ECHOSENS NORTH AMERICA, INC. | $92.24 |
| CELLTRION USA INC. | $76.39 |
| PFIZER INC. | $71.96 |
| LILLY USA, LLC | $66.86 |
| Other reporting companies | $323.69 |
Source: CMS 2025 payments grouped by covered recipient and nature of payments · Published Jun 30, 2026.
Professional details: NPI, taxonomy & registry record
Registry details
- Primary taxonomy
- Gastroenterology · Internal Medicine (CMS)
- Taxonomy code
- 207RG0100X
- Enumeration date
- Aug 25, 2005
- Record updated
- Feb 16, 2026
More registry details
- Provider type
- Individual · Type 1
- Reported credentials
- M.D.
Reported taxonomies and licenses
207RG0100X · Primary
License reported: MDR3G44 MO
207RG0100X
License reported: RG344 MO
License numbers and credentials are reported to NPPES; HCPList does not independently verify them.
Practice location
100 Village SqHazelwood, MO 63042-1820
- Phone
- (314) 355-4010
- Fax
- (314) 355-9484
Mailing address
PO BOX 23340SAINT LOUIS, MO 631563340
Information may be outdated or incomplete. Confirm details directly with the practice. HCPList is an independent directory and is not affiliated with CMS.
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