Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

Mark A Stonehill, MD

Individual provider Anesthesiology Physician · NPI 1740267335

Mark A Stonehill, MD practises Anesthesiology in Marietta, Ohio. Graduated from Indiana University School of Medicine in 2001, 25 years ago. Practices with Marietta Memorial Hospital, a 386-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in Indiana and Ohio.

Years since qualifying
25
Trained at
Indiana University School of Medicine
Licensed in
IN, OH
In the registry since
2005
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

401 Matthew St
Marietta, OH 45750-1635
Phone: (740) 376-1994
Fax: (740) 376-1940
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Additional practice locations (1)

  • 1106 Colegate Dr, Marietta, OH 45750-1323 — (740) 568-2000

Specialties & licences

Anesthesiology Physician (primary) Taxonomy 207L00000X · Licence 35099209 (OH)
Anesthesiology Physician Taxonomy 207L00000X · Licence 1060912 (IN)

Record details

NPI number1740267335
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedDecember 27, 2005
Last updated in NPPESSeptember 22, 2026
Certification dateSeptember 22, 2026

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyANESTHESIOLOGY
Medical schoolINDIANA UNIVERSITY SCHOOL OF MEDICINE
Graduated 2001 (25 years in practice)
Group practice Marietta Memorial Hospital — 386 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients194
Services billed 221 a service is one billed item, such as a visit, a test or a procedure
Average patient age72

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $22 1 payment · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician.

Colleagues at Marietta Memorial Hospital

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 386 clinicians in the practice; 12 are shown here.

Other providers in Marietta