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

David Alan Janssen, MD

Individual provider Infectious Disease Physician · NPI 1700995339

David Alan Janssen, MD is an Infectious Disease in O Fallon, Missouri. Graduated from Indiana University School of Medicine in 1988, 38 years ago. Practices with Fairview Heights Medical Group SC, a 448-clinician group, works from 2 locations and accepts Medicare assignment. Licensed in Illinois and Missouri.

Years since qualifying
38
Trained at
Indiana University School of Medicine
Licensed in
IL, MO
In the registry since
2006
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

20 Progress Point Pkwy Ste 206
O Fallon, MO 63368-2207
Phone: (636) 344-2014
Fax: (314) 747-1476
Show map & directions

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

Additional practice locations (1)

  • 621 S. New Ballas Road, St. Louis, MO 63141 — (314) 251-5700

Specialties & licences

Infectious Disease Physician (primary) Taxonomy 207RI0200X · Licence 208810309 (MO)
Specialist Taxonomy 174400000X · Licence 103905 (MO)
Infectious Disease Physician Taxonomy 207RI0200X · Licence 036176531 (IL)

Record details

NPI number1700995339
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedAugust 29, 2006
Last updated in NPPESOctober 21, 2025
Certification dateOctober 21, 2025
Mailing address20 Progress Point Pkwy Ste 206, O Fallon, MO 63368-2207

Medicare enrollment

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

Medicare specialtyINFECTIOUS DISEASE
Medical schoolINDIANA UNIVERSITY SCHOOL OF MEDICINE
Graduated 1988 (38 years in practice)
Group practice Fairview Heights Medical Group Sc — 448 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare