Physician Profile
Unclaimed ProfileAbout MARSHALL
Jacob C. Marshall, M.D. practices family medicine in O Fallon, IL. Jacob is also listed as specializing in emergency medicine. Medicare claims data shows Jacob provided 42 services to 41 patients.
Summarised automatically from public NPI registry and CMS Medicare data. Not written or reviewed by this provider. Claim this profile to replace it.
Areas of Expertise
Licensing & Certification
Source: NPPES NPI Registry
Contact Information
- (888) 577-6337
- Email not available
Practice Locations
103 N OAK ST
O Fallon, IL 62269
Procedures Most Often Billed to Medicare
42 services · 41 patients · 2 distinct codes
| Procedure | Type | Code | Services |
|---|---|---|---|
| Emergency department visit with high level of medical decision making | Office visit | 99285 |
23 |
| Emergency department visit with moderate level of medical decision making | Office visit | 99284 |
19 |
Source: CMS Medicare public data. Shows how often procedures were billed — not quality of care or patient satisfaction.
Related providers
Connections drawn from the registry and from what providers have told us. A link here is not a referral or an endorsement.
Also at this address 4
Providers at the same street address. Each files their own registry entry, so a shared practice often appears under several different names.
Other family doctors in O Fallon 8
Same specialty, same city.
Common questions
What kind of doctor is Dr. Marshall?
Dr. Marshall is a family doctor in O Fallon, IL. This is the primary taxonomy recorded against the NPI in the federal registry, listed there as “Family Medicine”.
NPI registry
What is Dr. Marshall's address?
Dr. Marshall is listed at 103 N OAK ST, O Fallon, IL 62269. Addresses come from the NPI registry and can lag a move, so confirm before travelling.
NPI registry
How can I make an appointment with Dr. Marshall?
The number on file is (888) 577-6337. Guide.md cannot book appointments or pass on messages — please call the office directly.
NPI registry
What is the NPI for Dr. Marshall?
Dr. Marshall's National Provider Identifier is 1922081249. It is issued by the Centers for Medicare & Medicaid Services and is unique and permanent — it does not change if they move practice.
NPI registry
How much experience does Dr. Marshall have?
Dr. Marshall has 21+ years experience. Registered with an NPI since 2005. National Provider Identifiers only began in 2005, so a provider who qualified earlier may have practiced for longer than this.
NPI registry
What procedures does Dr. Marshall perform?
According to Medicare billing data, Dr. Marshall the Medicare record under this individual NPI shows mainly office visits and diagnostic testing. Hospital-based physicians usually have their procedural work billed by the facility rather than under their own number, so this is a floor on their practice, not a description of it. This reflects Medicare patients only and is billing volume, not a measure of quality.
Medicare claims
Is Dr. Marshall's profile verified?
Not yet. This profile is built from public federal data and has not been confirmed by Dr. Marshall. If this is you, claiming it is free.
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Claim this profileProvider data sourced from the NPPES NPI Registry and CMS public datasets. Information is provided for reference and is not medical advice.