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

Robert J Grass, MD

Individual provider Adolescent Medicine (Internal Medicine) Physician · NPI 1689665093

Robert J Grass, MD is an Internal Medicine in Fond Du Lac, Wisconsin. Graduated from Medical College of Wisconsin in 1997, 29 years ago. Practices with Agnesian Healthcare Inc, a 390-clinician group and accepts Medicare assignment. Licensed in Wisconsin.

Years since qualifying
29
Trained at
Medical College of Wisconsin
Licensed in
WI
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

420 E Division St
Fond Du Lac, WI 54935-4560
Phone: (920) 926-8615
Show map & directions

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

Specialties & licences

Internal Medicine Physician (primary) Taxonomy 207R00000X · Licence 43234 (WI)
Adolescent Medicine (Internal Medicine) Physician Taxonomy 207RA0000X · Licence 43234 (WI)
Pediatrics Physician Taxonomy 208000000X · Licence 43234 (WI)

Record details

NPI number1689665093
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedNovember 3, 2005
Last updated in NPPESOctober 18, 2024
Certification dateOctober 18, 2024
Mailing address420 E Division St, Fond Du Lac, WI 54935-4560

Medicare enrollment

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

Medicare specialtyINTERNAL MEDICINE
Also practisesPEDIATRIC MEDICINE
Medical schoolMEDICAL COLLEGE OF WISCONSIN
Graduated 1997 (29 years in practice)
Group practice Agnesian Healthcare Inc — 390 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount

Other providers in Fond Du Lac