Quick answers
- Which hospitals does Mark B. Deyoung work at?
- Medicare's official clinician data lists Mark B. Deyoung at 4 hospitals: Graham Hospital Association, OSF Saint Luke Medical Center, Saint Francis Medical Center and St Mary Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark B. Deyoung see patients?
- Medicare's clinician data lists 2 practice locations, including Elmwood, IL and Williamsfield, IL. Call before your visit to confirm the address.
- What is Mark B. Deyoung's specialty?
- Medicare lists Family Practice as the primary specialty.
- Does Mark B. Deyoung accept Medicare assignment?
- Yes. Medicare's clinician data says Mark B. Deyoung accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is the phone number for Mark B. Deyoung?
- (309) 742-6334, as listed in official Medicare / NPI Registry data.
- What is Mark B. Deyoung's NPI number?
- 1306845045. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Mark B. Deyoung works
Medicare's Facility Affiliation Data lists Mark B. Deyoung at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Graham Hospital AssociationCanton, IL · Acute Care Hospital · CCN 140001
- OSF Saint Luke Medical CenterKewanee, IL · Critical Access Hospital · CCN 141325
- Saint Francis Medical CenterPeoria, IL · Acute Care Hospital · CCN 140067
- St Mary Medical CenterGalesburg, IL · Acute Care Hospital · CCN 140064
Practice locations
Addresses where Mark B. Deyoung is enrolled with Medicare (CMS data updated 2026-10-02).
- 1024 N Magnolia StElmwood, IL 61529 (309) 742‑6334
- 120 E Gale StWilliamsfield, IL 61489 (309) 639‑4004
Group practices
Medicare enrollment lists Mark B. Deyoung as a member of this group (CMS data updated 2026-10-02).
- Graham Hospital Association126 clinicians in the group
Specialties
- Family Practiceprimary
Other family doctors in Illinois
Clinicians with the same Medicare primary specialty in Illinois — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Michigan Medical School |
| Graduation year | 1978 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1306845045 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians