Mark Fesenmyer, MD
NPI 1992770390 · Gastroenterology Physician · Merrillville, IN
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Mark Fesenmyer, MD is a Gastroenterology Physician provider in Merrillville, IN (NPI 1992770390).
Provider details
- NPI number
- 1992770390
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Male
- Sole proprietor
- No
- License
- 036105597 (IL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
20 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
3 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
1,213 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 173 | $119 |
| Subsequent Hospital Care With Moderate Levelof Medical Decision Making, If Using Time, at Least 35 Minutes99232 | 157 | $71 |
| Initial Hospital Care With Moderate Level of Medical Decision Making, If Using Time, at Least 75 Minutes99223 | 129 | $159 |
| Removal of Polyps Or Growths of Large Bowel Using an Endoscope With Mechanical Snare45385 | 116 | $223 |
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 111 | $84 |
| Visit Complexity Inherent to Evaluation and Management Associated With Medical Care Services That Serve As the Continuing Focal Point for All Needed Health Care Services And/Or With Medical Care Services That Are Part of Ongoing Care Related to a Patient'S |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 21 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Pantoprazole Sodium | 321 | 109 |
| Peg3350/Sod Sulf,bicarb,cl/Kclbrand: Gavilyte-C | 219 | 211 |
| Omeprazole | 165 | 66 |
| Nortriptyline Hcl | 87 | 25 |
| Dicyclomine Hcl | 78 | 29 |
| Metoclopramide Hcl | 62 | 17 |
| Esomeprazole Magnesium | 50 | 16 |
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$1,125 across 56 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (2)
- 7835 Grand BlvdHobart, IN 46342-6665Phone: (219) 947-6795Fax: (219) 703-6896
- 3800 Saint Mary Rd Ste 101Valparaiso, IN 46383-3986Phone: (219) 947-6795Fax: (219) 703-6896
Registry dates
- Enumerated
- 2006-02-20
- Last updated
- 2020-05-05
- Certified
- 2020-05-05
Frequently asked questions
- What is Mark Fesenmyer's NPI number?
- Mark Fesenmyer's National Provider Identifier (NPI) is 1992770390, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Mark Fesenmyer's specialty?
- Mark Fesenmyer is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Mark Fesenmyer located?
- Mark Fesenmyer's practice location on file with NPPES is 8895 Broadway, Merrillville, IN 46410-7037.
- What is Mark Fesenmyer's phone number?
- The practice phone number listed in the NPPES registry for Mark Fesenmyer is (219) 738-2081.
- Does Mark Fesenmyer accept Medicare?
- Mark Fesenmyer is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Mark Fesenmyer's NPI active?
- Yes — Mark Fesenmyer's NPI (1992770390) is active in the NPPES registry as of the last update on 2020-05-05.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.