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

Dr. Guy William Felder, MD

Individual provider Internal Medicine Physician · NPI 1427159714

Dr. Guy William Felder, MD practises Internal Medicine in Saint Louis, Missouri. Graduated from Saint Louis University School of Medicine in 1988, 38 years ago. Practices with Mercy East Ambulatory Services LLC, a 103-clinician group and accepts Medicare assignment. Licensed in Missouri.

Years since qualifying
38
Trained at
Saint Louis University School of Medicine
Licensed in
MO
In the registry since
2006
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

5640C Telegraph Rd
Saint Louis, MO 63129-4243
Phone: (314) 293-4413
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

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence R8J13 (MO)

Record details

NPI number1427159714
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedSeptember 26, 2006
Last updated in NPPESNovember 13, 2025
Certification dateNovember 13, 2025

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Medical schoolSAINT LOUIS UNIVERSITY SCHOOL OF MEDICINE
Graduated 1988 (38 years in practice)
Group practice Mercy East Ambulatory Services Llc — 103 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 patients57
Services billed 63 a service is one billed item, such as a visit, a test or a procedure
Average patient age74

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.

Colleagues at Mercy East Ambulatory Services LLC

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 103 clinicians in the practice; 12 are shown here.

Other providers in Saint Louis