Dr. Nathan Philip Seigrist , DO
General Practice • O Fallon, IL
Professional Overview & Biography Verified Profile Summary
Dr. Nathan Seigrist, DO is a registered healthcare professional specializing in General Practice in O Fallon, IL. Practice services are available at 3 SAINT ELIZABETH BLVD STE 4000 under active NPI credentials.
Practice Location & Contact Primary Location
3 Saint Elizabeth Blvd Ste 4000
O Fallon, IL 622691284
Specialty Benchmarks & Practice Insights
Comparative analytics for General Practice in O Fallon, IL
Practicing in O Fallon, IL (355 Statewide)
In-Person Office Visits Only
Under CMS Medicare Fee Schedule vs Standard Submitted Charges
Medical Specialties & State Licenses
CMS Verified: 2026-06-24NUCC Taxonomy Code: 208D00000X
A physician who specializes in the general practice of diagnosing, treating, and managing patients with a variety of illnesses and conditions.
NUCC Taxonomy Code: 171000000X
Active duty military health care providers not otherwise classified who need to be separately identified for operational, clinical, or administrative processes.
NUCC Taxonomy Code: 390200000X
An individual who is enrolled in an organized health care education/training program leading to a degree, certification, registration, and/or licensure to provide health care.
Practice Associates & Co-Workers
Healthcare professionals and specialists practicing at this location or sharing practice phone/fax
Pharmacist
Doctor of Pharmacy (Pharm.D.)
Family Medicine
Doctor of Medicine (M.D.)
Registered Nurse
Registered Nurse
Social Worker - Clinical
Family Medicine
Doctor of Osteopathic Medicine (D.O.)
Surgery - Trauma Surgery
Doctor of Medicine (M.D.)
Career & Practice History Timeline
Chronological log of verified NPI updates, location relocations, credentials, and registry changes
Registered at 3 SAINT ELIZABETH BLVD STE 4000, O FALLON, IL 622691284 (Tel: 6182569355)
Registered at 3 SAINT ELIZABETH BLVD STE 4000, O FALLON, IL 622691284 (Tel: 6182569355)
Registered at 3551 ROGER BROOKE DR, FORT SAM HOUSTON, TX 782344504 (Tel: 2109164141)
Registered at 4306 LORING PARK, CONVERSE, TX 781093747 (Tel: 9726584680)
Recorded as NATHAN SEIGRIST, DO
Military Health Care Provider
NPI status registered as active in NPPES database
Registered at 5000 LAKEWOOD RANCH BLVD, BRADENTON, FL 342114909 (Tel: 9726584680)
Registered at 4511 SUMMER COVE DR E APT 423, SARASOTA, FL 342434978 (Tel: 9726584680)
Recorded as NATHAN SEIGRIST
Student in an Organized Health Care Education/Training Program
First registered as active Individual Practitioner in NPPES Database.
Patient & Community Reviews
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NPI Administrative Meta
Mailing Address
3 Saint Elizabeth Blvd Ste 4000
O Fallon, IL 622691284
Phone: 6182569355
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