Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.
NPIDirectory

Dr. Margaretta Lynn Mendenhall, MD

Individual provider Obstetrics & Gynecology Physician · NPI 1275730111

Dr. Margaretta Lynn Mendenhall, MD practises Obstetrics/Gynecology in O Fallon, Missouri. Graduated from Saint Louis University School of Medicine in 2007, 19 years ago. Practices with Mercy Clinic East Communities, a 573-clinician group and accepts Medicare assignment. Licensed in Missouri.

Years since qualifying
19
Trained at
Saint Louis University School of Medicine
Licensed in
MO
In the registry since
2007
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Claim this listing Report a problem Suggest an edit

Practice location Address checks out

300 Winding Woods Dr Ste 200
O Fallon, MO 63366-4771 Not confirmed with CMS for 12 years — call before visiting
Phone: (636) 240-0130
Fax: (636) 240-6822
Show map & directions

Directions in Google Maps · Apple Maps · OpenStreetMap

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Obstetrics & Gynecology Physician (primary) Taxonomy 207V00000X · Licence 2011009917 (MO)

Record details

NPI number1275730111
Entity typeIndividual (Type 1)
GenderFemale
Credentials MD
Sole proprietorNo
NPI enumeratedJuly 2, 2007
Last updated in NPPESMarch 11, 2014

Medicare enrollment

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

Medicare specialtyOBSTETRICS/GYNECOLOGY
Medical schoolSAINT LOUIS UNIVERSITY SCHOOL OF MEDICINE
Graduated 2007 (19 years in practice)
Group practice Mercy Clinic East Communities — 573 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 patients39
Services billed 51 a service is one billed item, such as a visit, a test or a procedure
Average patient age70

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 $274 13 payments · a meal or drink at a meeting or visit, not a fee
Education $80 1 payment · educational material or training, 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 Mercy Clinic East Communities

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 573 clinicians in the practice; 12 are shown here.

Other providers in O Fallon