Doctor profile · Federal record
Dr. Mark Fesenmyer, MD
Gastroenterology Physician (CMS: Gastroenterology) · Gastroenterology Physician · Merrillville, IN
- NPI 1992770390
- Accepts Medicare
- 35 yrs in practice
- Licensed in 2 states
- Male
- Group practice
- No sanctions
Practice & contact
Operates at 3 locations .
- Primary practice
-
8895 Broadway
Merrillville, IN 464107037
(219) 738-2081
fax (219) 736-4658 - Additional location
-
3800 Saint Mary RD Ste 101
Valparaiso, IN 463833986
(219) 947-6795
fax (219) 703-6896 - Additional location
-
7835 Grand Blvd
Hobart, IN 463426665
(219) 947-6795
fax (219) 703-6896
Credentials & registration
- NPI registered
- February 2006 — 20 yrs on file
- Profile last updated
- May 5, 2020
- Year of graduation
- 1991 — 35 yrs since
- Specialty taxonomy
- 207RG0100X — NUCC code
- State licenses (2)
- Indiana #01072085A · Illinois #036105597
- Medicaid (2)
- IL #036105597 · IN #201131780A
Federal sanctions & exclusions
No sanctions, exclusions or revocations on file
Checked against OIG LEIE on NPI 1992770390. Last verified May 11, 2026.Medicare procedures · 2023
Top services delivered
Total services
1,159
Distinct HCPCS
10
Medicare allowed
$143,247
| HCPCS | Description | Services | Patients | Avg allowed | |
|---|---|---|---|---|---|
99232 |
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes | 190 | 128 | $73 | |
99214 |
Established patient office or other outpatient visit, 30-39 minutes | 173 | 134 | $117 | |
99223 |
Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes | 130 | 128 | $160 | |
45385 |
Removal of polyps or growths of large bowel using an endoscope with mechanical snare | 108 | 107 | $219 | |
99213 |
Established patient office or other outpatient visit, 20-29 minutes | 94 | 87 | $84 | |
43239 |
Biopsy of esophagus, stomach, and/or upper small bowel using a flexible endoscope | 66 | 65 | $89 | |
99204 |
New patient office or other outpatient visit, 45-59 minutes | 58 | 58 | $153 | |
45380 |
Biopsy of large bowel using a flexible endoscope | 50 | 50 | $116 | |
45385 |
Removal of polyps or growths of large bowel using an endoscope with mechanical snare | 49 | 48 | $223 | |
99231 |
Subsequent hospital care with straightforward or low level of medical decision making, per day, if using time, at least 25 minutes | 44 | 44 | $46 |
In context: peer comparison
Among 2 peers in Merrillville Gastroenterology Physician, average services per provider: 54. This provider delivers 21× the peer median.Open Payments
Industry payments received
All-time total
$1,125
Transactions
55
Manufacturers
15
| Payer (manufacturer) | Industry | Txns | Amount |
|---|---|---|---|
| Abbvie INC. | 18 | $355.23 | |
| Takeda Pharmaceuticals U.S.A., INC. | 9 | $173.21 | |
| Mallinckrodt Hospital Products INC. | 1 | $92.36 | |
| Phathom Pharmaceuticals, INC. | 5 | $88.50 | |
| Janssen Biotech, INC. | 5 | $86.47 | |
| Lilly USA, LLC | 4 | $77.46 | |
| Pfizer INC. | 3 | $48.46 | |
| Celgene Corporation | 2 | $42.58 | |
| Ironwood Pharmaceuticals, INC | 2 | $35.88 | |
| Ardelyx, INC. | 1 | $22.85 | |
| Gilead Sciences, INC. | 1 | $19.44 | |
| Evoke Pharma, INC. | 1 | $18.37 | |
| Qol Medical, LLC | 1 | $18.34 | |
| Salix Pharmaceuticals, A Division of Bausch Health US, LLC | 1 | $17.48 | |
| Braintree Laboratories, INC. | 1 | $14.50 |
By nature of payment
Medicare Part D · 2023
Top prescriptions
Total claims
1,309
Patients
616
Total drug cost
$120,585
| Drug | Type | Claims | Patients | Total cost |
|---|---|---|---|---|
| Pantoprazole Sodium | Generic | 330 | 117 | $8,585 |
| Gavilyte-C (Peg3350/Sod Sulf,Bicarb,Cl/Kcl) | Brand | 285 | 279 | $5,101 |
| Omeprazole | Generic | 144 | 53 | $2,407 |
| Dicyclomine Hcl | Generic | 102 | 35 | $3,903 |
| Nortriptyline Hcl | Generic | 92 | 28 | $1,271 |
| Metoclopramide Hcl | Generic | 61 | 13 | $730 |
| Sucralfate | Generic | 56 | 17 | $12,134 |
| Esomeprazole Magnesium | Generic | 55 | 17 | $7,112 |
| Movantik (Naloxegol Oxalate) | Brand | 29 | 0 | $13,919 |
| Sod Sulf-Potass Sulf-Mag Sulf (Sodium, Potassium,Mag Sulfates) | Brand | 29 | 29 | $1,974 |
Hospital affiliations
Frequently asked questions
What is Dr. Mark Fesenmyer's medical specialty?
Dr. Mark Fesenmyer practices Gastroenterology Physician in Merrillville, IN.
Where does Dr. Mark Fesenmyer practice?
Dr. Mark Fesenmyer practices at 8895 Broadway, Merrillville, IN 464107037. Office phone: 2197382081.
What is Dr. Mark Fesenmyer's NPI?
Dr. Mark Fesenmyer's National Provider Identifier (NPI) is 1992770390, issued by NPPES.
Does Dr. Mark Fesenmyer accept Medicare assignment?
Yes. Dr. Mark Fesenmyer accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Mark Fesenmyer commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Established patient office or other outpatient visit (HCPCS 99214); Initial hospital care with moderate level of medical decision making (HCPCS 99223). Source: CMS Medicare Physician & Other Practitioners file.