Quick answers
- Which hospitals does Mark H. Gregory work at?
- Medicare's official clinician data lists Mark H. Gregory at 5 hospitals: Barnes Jewish Hospital, Barnes-Jewish West County Hospital, Mercy Hospital St Louis, Missouri Baptist Medical Center and Northwestern Medicine Central Dupage Hospital. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Mark H. Gregory see patients?
- Medicare's clinician data lists 1 practice location in Saint Louis, MO. Call before your visit to confirm the address.
- What is Mark H. Gregory's specialty?
- Medicare lists Internal Medicine as the primary specialty.
- Does Mark H. Gregory accept Medicare assignment?
- Yes. Medicare's clinician data says Mark H. Gregory 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.
- Does Mark H. Gregory offer telehealth?
- Medicare's clinician data says Mark H. Gregory offers telehealth services. Ask the office which visits can be done by video or phone.
- What is the phone number for Mark H. Gregory?
- (314) 872-8470, as listed in official Medicare / NPI Registry data.
- What is Mark H. Gregory's NPI number?
- 1104843663. 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 H. Gregory works
Medicare's Facility Affiliation Data lists Mark H. Gregory at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Barnes Jewish HospitalSaint Louis, MO · Acute Care Hospital · CCN 260032
- Barnes-Jewish West County HospitalCreve Coeur, MO · Acute Care Hospital · CCN 260162
- Mercy Hospital St LouisSaint Louis, MO · Acute Care Hospital · CCN 260020
- Missouri Baptist Medical CenterSaint Louis, MO · Acute Care Hospital · CCN 260108
- Northwestern Medicine Central Dupage HospitalWinfield, IL · Acute Care Hospital · CCN 140242
Practice locations
Addresses where Mark H. Gregory is enrolled with Medicare (CMS data updated 2026-10-02).
- 555 N New Ballas Rd, Suite 110Saint Louis, MO 63141 (314) 872‑8470
Specialties
- Internal Medicineprimary
Other internal 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 Vermont College Of Medicine |
| Graduation year | 1986 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| Telehealth | Offers telehealth services |
| NPI (National Provider Identifier) | 1104843663 |
| 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