Recently Updated NPI Information — some details in this NPI profile have been updated in the NPI registry within the last 60 days.

NATHAN PHILIP SEIGRIST DO
NPI 1780382465
General Practice in O Fallon, IL

Q: What is Nathan Seigrist's NPI number?

The NPI number for Nathan Seigrist is 1780382465. It was assigned to this individual provider in the NPPES registry on February 21, 2023.

Q: What is Nathan Seigrist's specialty?

The primary specialty registered for this NPI is General Practice with taxonomy code 208D00000X.

Q: When was this NPI record last updated?

The NPPES record for Nathan Seigrist was last updated on June 24, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 59 days ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since February 21, 2023PECOS Enrolled

3 SAINT ELIZABETH BLVD STE 4000, O FALLON, IL 62269(618) 256-9355(618) 206-2332 Get Directions Write a Review

NPPES record last updated: June 24, 2026. Verified against the NPPES registry weekly; last sync: August 16, 2026.

Record update history: Jun 9, 2024, Aug 22, 2023, Feb 21, 2023 (3 updates tracked since 2023).

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About Nathan Philip Seigrist Do NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

NATHAN PHILIP SEIGRIST DO (NPI 1780382465) is an individual general practice provider in O Fallon, Illinois, licensed in Florida (OS23985) and active in the NPI registry since February 2023. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1780382465

Entity TypeIndividualMale

Primary Taxonomy208D00000X

Provider Legal NameNATHAN PHILIP SEIGRISTCredential: DO

Location Address3 SAINT ELIZABETH BLVD STE 4000O Fallon, IL 62269-1284

Mailing Address3 Saint Elizabeth Blvd Ste 4000O Fallon, IL 62269-1284 · (618) 256-9355 · Fax (618) 206-2332

Phone(618) 256-9355

Fax(618) 206-2332

Sole ProprietorYes

Enumeration DateFebruary 21, 2023

Last NPPES UpdateJune 24, 20263 updates tracked since enumeration

NPPES CertifiedJune 24, 2026

✔ NPI 1780382465 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 3

★ Primary SpecialtyGeneral PracticeAllopathic & Osteopathic Physicians

Taxonomy Code208D00000X

License✔ Licensed in FL · OS23985

Definition

A physician who specializes in the general practice of diagnosing, treating, and managing patients with a variety of illnesses and conditions. Source: National Uniform Claim Committee

Also ListedMilitary Health Care ProviderTaxonomy 171000000X

Also ListedStudent in an Organized Health Care Education/Training ProgramTaxonomy 390200000X · License 125.084301 (IL)

3 SAINT ELIZABETH BLVD STE 4000, O Fallon, IL 62269

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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, and ordering and referring status from the CMS PECOS system.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Nathan Philip Seigrist Do is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Other Providers at the Same Location NPPES 20

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

MARA GRACE DOWNING MD

Student in an Organized Health Care Education/Training Program