Quick answers
- Which hospitals does Mark A. Mason work at?
- Medicare's official clinician data lists Mark A. Mason at 3 hospitals: Pike County Memorial Hospital, SSM Health Saint Louis University Hospital and Washington County Memorial Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark A. Mason see patients?
- Medicare's clinician data lists 3 practice locations, including Saint Louis, MO, Louisiana, MO and Potosi, MO. Call before your visit to confirm the address.
- What is Mark A. Mason's specialty?
- Medicare lists Emergency Medicine as the primary specialty, and also Family Practice.
- Does Mark A. Mason accept Medicare assignment?
- Yes. Medicare's clinician data says Mark A. Mason 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 A. Mason?
- (314) 617-2000, as listed in official Medicare / NPI Registry data.
- What is Mark A. Mason's NPI number?
- 1134167091. 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 A. Mason works
Medicare's Facility Affiliation Data lists Mark A. Mason at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Pike County Memorial HospitalLouisiana, MO · Critical Access Hospital · CCN 261333
- SSM Health Saint Louis University HospitalSaint Louis, MO · Acute Care Hospital · CCN 260105
- Washington County Memorial HospitalPotosi, MO · Critical Access Hospital · CCN 261308
Practice locations
Addresses where Mark A. Mason is enrolled with Medicare (CMS data updated 2026-10-02).
- 1201 S Grand BlvdSaint Louis, MO 63104 (314) 617‑2000
- 2305 Georgia StLouisiana, MO 63353 (573) 754‑5531
- 300 Health Way DrPotosi, MO 63664 (573) 438‑5451
Group practices
Medicare enrollment lists Mark A. Mason as a member of these groups (CMS data updated 2026-10-02).
- SSM Health Care Group940 clinicians in the group
- Southeastern Emergency Physicians of Memphis LLC94 clinicians in the group
- Potosi Emergency Group, LLC19 clinicians in the group
Specialties
- Emergency Medicineprimary
- Family Practicealso
Other emergency medicine doctors in Saint Louis
Clinicians with the same Medicare primary specialty in Saint Louis, MO — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | University Of Michigan Medical School |
| Graduation year | 1985 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1134167091 |
| 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