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

Dr. Gerard John Diefes, MD

Individual provider Critical Care Medicine (Internal Medicine) Physician · NPI 1417948951

Dr. Gerard John Diefes, MD is a Pulmonary Disease in Wynnewood, Pennsylvania. Graduated from Hahnemann University College of Medicine in 1992, 34 years ago. Practices with Advocare, LLC, a 385-clinician group, works from 2 locations, accepts Medicare assignment and offers telehealth. Licensed in Pennsylvania.

Years since qualifying
34
Trained at
Hahnemann University College of Medicine
Licensed in
PA
In the registry since
2005
Specialties on file
3
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

1001 City Line Ave Wb 113
Wynnewood, PA 19096-3902
Phone: (610) 896-0280
Fax: (610) 896-0286
Show map & directions

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

Additional practice locations (1)

  • 736 W Lincoln Hwy, Exton, PA 19341-2547 — (610) 359-5858

Specialties & licences

Pulmonary Disease Physician (primary) Taxonomy 207RP1001X · Licence MD056949L (PA)
Critical Care Medicine (Internal Medicine) Physician Taxonomy 207RC0200X · Licence MD056949L (PA)
Sleep Medicine (Internal Medicine) Physician Taxonomy 207RS0012X · Licence MD056949L (PA)

Record details

NPI number1417948951
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedNovember 3, 2005
Last updated in NPPESMay 20, 2025
Certification dateMay 20, 2025

Medicare enrollment

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

Medicare specialtyPULMONARY DISEASE
Also practisesCRITICAL CARE (INTENSIVISTS), INTERNAL MEDICINE, SLEEP MEDICINE
Medical schoolHAHNEMANN UNIVERSITY COLLEGE OF MEDICINE
Graduated 1992 (34 years in practice)
Group practice Advocare, Llc — 385 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
TelehealthOffers telehealth services
Practice locations3 on file with Medicare