Mark Fesenmyer, MD
Gastroenterology (CMS) · Merrillville, IN
At a glance
8895 Broadway, Merrillville, IN 46410-7037
Published activity: Colonoscopy · Upper gastrointestinal (GI) endoscopy for acid reflux. View counts and coverage
NPPES record updated May 5, 2020. 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
8895 BroadwayMerrillville, IN 46410-7037
Additional reported practice locations
7835 Grand BlvdHobart, IN 463426665
Phone: 2199476795
Fax: 2197036896 3800 Saint Mary Rd Ste 101
Valparaiso, IN 463833986
Phone: 2199476795
Fax: 2197036896
Education & affiliations
- Medical / professional school
- Indiana University School Of Medicine
- Graduation year
- 1991
- CMS specialties
- Gastroenterology
Practice groups
Reported hospital affiliations
- Community Hospital Munster, IN
- St Catherine Hospital Inc East Chicago, IN
- St Mary Medical Center Inc Hobart, IN
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 | 139 |
| Upper gastrointestinal (GI) endoscopy for acid reflux | 138 |
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 | $1,053.88 |
Reporting companies
| Company | Amount |
|---|---|
| TAKEDA PHARMACEUTICALS U.S.A., INC. | $218.33 |
| ABBVIE INC. | $204.15 |
| JANSSEN BIOTECH, INC. | $164.09 |
| PHATHOM PHARMACEUTICALS, INC. | $97.42 |
| AIMMUNE THERAPEUTICS, INC. | $79.85 |
| MADRIGAL PHARMACEUTICALS | $72.95 |
| ARDELYX, INC. | $71.10 |
| CELLTRION USA INC. | $65.82 |
| Other reporting companies | $80.17 |
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 (CMS)
- Taxonomy code
- 207RG0100X
- Enumeration date
- Feb 20, 2006
- Record updated
- May 5, 2020
More registry details
- Provider type
- Individual · Type 1
- Reported credentials
- MD
Reported taxonomies and licenses
207RG0100X
License reported: 036105597 IL
207RG0100X · Primary
License reported: 01072085A IN
License numbers and credentials are reported to NPPES; HCPList does not independently verify them.
Practice location
8895 BroadwayMerrillville, IN 46410-7037
- Phone
- (219) 738-2081
- Fax
- (219) 736-4658
Mailing address
8895 BROADWAYMERRILLVILLE, IN 464107037
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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