Quick answers
- Which hospitals does David A. Janssen work at?
- Medicare's official clinician data lists David A. Janssen at 3 hospitals: Memorial Hospital, Parkland Health Center and Progress West Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does David A. Janssen see patients?
- Medicare's clinician data lists 2 practice locations, including Alton, IL and O Fallon, MO. Call before your visit to confirm the address.
- What is David A. Janssen's specialty?
- Medicare lists Infectious Disease as the primary specialty.
- Does David A. Janssen accept Medicare assignment?
- Yes. Medicare's clinician data says David A. Janssen 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 David A. Janssen?
- (618) 463-8500, as listed in official Medicare / NPI Registry data.
- What is David A. Janssen's NPI number?
- 1700995339. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where David A. Janssen works
Medicare's Facility Affiliation Data lists David A. Janssen at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Memorial HospitalBelleville, IL · Acute Care Hospital · CCN 140185
- Parkland Health CenterFarmington, MO · Acute Care Hospital · CCN 260163
- Progress West HospitalOfallon, MO · Acute Care Hospital · CCN 260219
Practice locations
Addresses where David A. Janssen is enrolled with Medicare (CMS data updated 2026-10-02).
- 1 Professional DrAlton, IL 62002 (618) 463‑8500
- 20 Progress Point PkwyO Fallon, MO 63368 (636) 916‑7060
Group practices
Medicare enrollment lists David A. Janssen as a member of this group (CMS data updated 2026-10-02).
- Fairview Heights Medical Group SC444 clinicians in the group
Specialties
- Infectious Diseaseprimary
Other infectious disease doctors in Alton
Clinicians with the same Medicare primary specialty in Alton, IL — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Indiana University School Of Medicine |
| Graduation year | 1988 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1700995339 |
| 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