Quick answers
- Which hospitals does Mark P. Demus work at?
- Medicare's official clinician data lists Mark P. Demus at 2 hospitals: Northwest Community Hospital 1 and St Alexius Medical Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark P. Demus see patients?
- Medicare's clinician data lists 8 practice locations, including Buffalo Grove, IL, Hoffman Estates, IL and Mount Prospect, IL. Call before your visit to confirm the address.
- What is Mark P. Demus's specialty?
- Medicare lists Internal Medicine as the primary specialty, and also Emergency Medicine.
- Does Mark P. Demus accept Medicare assignment?
- Yes. Medicare's clinician data says Mark P. Demus 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 P. Demus?
- (847) 725-8640, as listed in official Medicare / NPI Registry data.
- What is Mark P. Demus's NPI number?
- 1477571479. 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 P. Demus works
Medicare's Facility Affiliation Data lists Mark P. Demus at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Northwest Community Hospital 1Arlington Heights, IL · Acute Care Hospital · CCN 140252
- St Alexius Medical CenterHoffman Estates, IL · Acute Care Hospital · CCN 140290
Practice locations
Addresses where Mark P. Demus is enrolled with Medicare (CMS data updated 2026-10-02). The first 5 of 8; the Medicare profile lists all.
- 1450 Busch PkwyBuffalo Grove, IL 60089 (847) 725‑8640
- 1555 Barrington RdHoffman Estates, IL 60169 (847) 843‑2000
- 199 W Rand RdMount Prospect, IL 60056 (847) 618‑5400
- 21481 N Rand RdKildeer, IL 60047 (847) 618‑9696
- 21481 N Rand Rd, Fl 2Kildeer, IL 60047 (847) 866‑7846
Group practices
Medicare enrollment lists Mark P. Demus as a member of these groups (CMS data updated 2026-10-02).
- Endeavor Health Medical Group3,350 clinicians in the group
- Cepamerica Illinois LLP499 clinicians in the group
Specialties
- Internal Medicineprimary
- Emergency Medicinealso
Other internal medicine doctors in Buffalo Grove
Clinicians with the same Medicare primary specialty in Buffalo Grove, IL — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Northwestern University Feinberg Medical School |
| Graduation year | 1981 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1477571479 |
| 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