Dr. Mark E. Fesenmyer, MD
- Medicare services, 2024
- 1,213
- Medicare patients, 2024
- 655
- Part D claims, 2024
- 1,432
- Hospital affiliations
- 4
- Industry payments
- $2,179
- Practice address
- 1500 S Lake Park Ave, Hobart, IN 46342
- Practice phone
- Call (219) 942-0551
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
St Mary Medical Center (IN)
Hobart, Indiana
Find Dr. Fesenmyer's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. Mark E. Fesenmyer is a gastroenterologist in Hobart, Indiana
Dr. Fesenmyer practices at St Mary Medical Center (IN) in Hobart, Indiana.
Dr. Fesenmyer's NPI, 1992770390, was assigned on February 20, 2006. Dr. Fesenmyer graduated from Indiana University School of Medicine in 1991. Dr. Fesenmyer holds Indiana license 01072085A.
- NPI
- 1992770390NPI Registry (opens in a new tab)
- Medicare PAC ID
- 7416842810
- NPI enumeration date
- February 20, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (219) 942-0551
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 61
- Medical school graduation
- 1991
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Practice Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Mark E. Fesenmyer practices at St Mary Medical Center (IN) in Hobart, Indiana
Dr. Fesenmyer's primary practice is St Mary Medical Center (IN), at 1500 S Lake Park Ave, Hobart, IN 46342 in Lake County. The practice phone is (219) 942-0551.
- St Mary Medical Center (IN)1500 S Lake Park Ave, Hobart, IN 46342 · Lake CountyPhone(219) 942-0551
Sources: NPPES NPI Registry (CMS); and Dmand AI Practice Data
Dr. Mark E. Fesenmyer is affiliated with 7 sites of care and 2 medical groups
Dr. Fesenmyer's primary practice is St Mary Medical Center (IN) in Hobart, Indiana. Dr. Fesenmyer is also affiliated with St. Mary Medical Center. The medical group on file is Powers Health Medical Group. Dmand AI also links Dr. Fesenmyer to 3 more hospitals, 2 group practices and clinics and 1 medical group, each named with a free account.
Sources: NPPES NPI Registry (CMS); Dmand AI Practice Data; Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Mark E. Fesenmyer's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Fesenmyer practices, 6 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| St Mary Medical Center (IN) | Available with a free account |
| +6 more sites and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Mark E. Fesenmyer is one of 333 gastroenterologists in Indiana
Gastroenterology is Dr. Fesenmyer's primary specialty in the NPI Registry, under taxonomy code 207RG0100X. Dmand AI has Dr. Fesenmyer's licenses on file in 2 states: Indiana and Illinois.
Specialties and state licenses
- Gastroenterology, IndianaPrimary
- Illinois license
Gastroenterologists near Dr. Fesenmyer
Counts of gastroenterologists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Mark E. Fesenmyer billed Medicare for 1,213 services in 2024
CMS data shows 1,213 Medicare services from Dr. Fesenmyer across 16 procedure codes in 2024, for 655 Medicare patients. Medicare paid $112,799 for them.
Dr. Fesenmyer's Medicare services by type, 2024
- Office and hospital visits722
- Surgery371
- Other services120
Where Dr. Fesenmyer's Medicare services took place, 2024
- In an office51643%
- In a facility69757%
Dr. Fesenmyer compared with the Indiana median for gastroenterologists, 2024
- Dr. Fesenmyer
- Indiana median
- Medicare services
- 1,213vs 4712.6 times
- Medicare patients
- 655vs 3092.1 times
- Part D claims
- 1,245vs 4223.0 times
Medians across 330 gastroenterologists in Indiana with Dmand AI profiles that report each measure.
Dr. Fesenmyer's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Fesenmyer and other gastroenterologists in Indiana.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Mark E. Fesenmyer treated 655 Medicare patients in 2024, average age 73
CMS counts 655 Medicare patients who saw Dr. Fesenmyer in 2024. The largest group is 65 to 74, with 302 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 13% are also on Medicaid. Their average risk score is 1.66, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Fesenmyer's median patient age at 69, with 56% women.
Dr. Fesenmyer's Medicare patients by age, 2024
Dr. Fesenmyer's Medicare patients by sex, 2024
- Women39260%
- Men26340%
Chronic conditions among Dr. Fesenmyer's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis56%
- Diabetes37%
- Ischemic heart disease34%
- Chronic kidney disease31%
- Anxiety29%
- Mood disorders28%
Share of Medicare patients with each condition. A patient can have several.
Dr. Fesenmyer's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 69
Patient panel by sex, all payers
- Women56%
- Men43%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Mark E. Fesenmyer wrote 1,432 Medicare Part D claims in 2024
In 2024, Dr. Fesenmyer wrote 1,432 Medicare Part D claims for 545 patients. 90% of them were for generic drugs. CMS names the drug for 1,245 of them, across 21 drugs with 11 or more claims each, at $160,279 in total drug cost.
Dr. Fesenmyer's Part D claims by kind of drug, 2024
- Generic1,283 claims90%
- Brand-name and other149 claims10%
Dr. Fesenmyer's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Fesenmyer's Part D claims, 2024
- Antibiotics2%28 of 1,432 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
Dr. Mark E. Fesenmyer ranks in the 87th percentile for colonoscopy in Medicare
Dr. Fesenmyer accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS counts 139 procedures of colonoscopy by Dr. Fesenmyer, more than 87% of the clinicians it reports for that procedure.
- Accepts Medicare assignment
- Yes
Where Dr. Fesenmyer ranks in Medicare procedure volume
- Colonoscopy
- 87th percentile139 procedures
- Upper gastrointestinal (GI) endoscopy for acid reflux
- 83rd percentile138 procedures
CMS ranks each clinician against every clinician it reports for the same procedure category.
Sources: Doctors and Clinicians National Downloadable File (CMS); and Doctors and Clinicians Utilization Data (CMS)
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Dr. Mark E. Fesenmyer received $2,179 in industry payments from 2024 to 2025
CMS Open Payments shows 110 general payments to Dr. Fesenmyer from 19 drug and device companies from 2024 to 2025. Food and beverage make up the largest share, 100% of the total. Abbvie Inc. paid the most, $559.
General payments to Dr. Fesenmyer by program year, 2024 to 2025
Companies that paid Dr. Fesenmyer the most, 2024 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Mark E. Fesenmyer graduated from Indiana University School of Medicine
Dr. Fesenmyer graduated from Indiana University School of Medicine in 1991.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Mark E. Fesenmyer's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice Data |
| Primary practice, affiliations and health system | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Practice DataDmand AI Affiliation DataDmand AI Org Hierarchy Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab)Doctors and Clinicians Utilization Data (CMS) (opens in a new tab) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Mark E. Fesenmyer
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Mark E. Fesenmyer's NPI number?
Dr. Mark E. Fesenmyer's NPI number is 1992770390. It was assigned on February 20, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Mark E. Fesenmyer?
Dr. Mark E. Fesenmyer is a gastroenterologist in Hobart, Indiana. The primary specialty in the NPI Registry is Gastroenterology Physician (taxonomy code 207RG0100X).
Where does Dr. Mark E. Fesenmyer practice?
Dr. Fesenmyer practices at 1500 S Lake Park Ave, Hobart, IN 46342. Dr. Fesenmyer's primary practice is St Mary Medical Center (IN) in Hobart, Indiana. Dmand AI also links Dr. Fesenmyer to 3 hospitals, 2 group practices and clinics and 1 medical group.
What is Dr. Mark E. Fesenmyer's office phone number?
The practice phone on file for Dr. Fesenmyer is (219) 942-0551.
What is Dr. Mark E. Fesenmyer's medical license number?
Dr. Fesenmyer holds Indiana license 01072085A, one of the licenses on file in 2 states.
Which states has Dr. Mark E. Fesenmyer been licensed in?
Dmand AI has state licenses on file for Dr. Fesenmyer in Indiana and Illinois.
Which hospitals is Dr. Mark E. Fesenmyer affiliated with?
Dr. Fesenmyer is affiliated with St. Mary Medical Center. Dmand AI links Dr. Fesenmyer to 3 more hospitals.
What medical group is Dr. Mark E. Fesenmyer part of?
Dr. Fesenmyer is linked to Powers Health Medical Group. Dmand AI links Dr. Fesenmyer to 1 more medical group.
Does Dr. Mark E. Fesenmyer accept Medicare?
Yes. CMS data shows Dr. Fesenmyer billed Medicare for 1,213 services in 2024, and Dr. Fesenmyer accepts Medicare assignment.
How many Medicare patients does Dr. Mark E. Fesenmyer see?
CMS counts 655 Medicare patients who saw Dr. Fesenmyer in 2024, with an average age of 73.
Show 5 more questionsShow fewer questions
What services does Dr. Mark E. Fesenmyer bill to Medicare?
In 2024, Dr. Fesenmyer's most billed Medicare services were surgery: digestive system (45385), office visit, established patient (99214) and hospital inpatient care (99232).
Where did Dr. Mark E. Fesenmyer go to medical school?
Dr. Fesenmyer graduated from Indiana University School of Medicine in 1991.
What drugs does Dr. Mark E. Fesenmyer prescribe most?
In 2024 Medicare Part D data, Dr. Fesenmyer's most prescribed drugs by claims were Pantoprazole Sodium, Gavilyte-C and Omeprazole.
Has Dr. Mark E. Fesenmyer received payments from drug or device companies?
CMS Open Payments shows $2,179 in general payments to Dr. Fesenmyer from 19 companies from 2024 to 2025. The largest total came from Abbvie Inc.
How long has Dr. Mark E. Fesenmyer been practicing?
Dr. Fesenmyer graduated from medical school in 1991, 35 years ago.
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