Quick answers
- Which hospitals does John G. Mellas work at?
- Medicare's official clinician data lists John G. Mellas at 4 hospitals: Missouri Baptist Medical Center, Northwestern Medicine Central Dupage Hospital, SSM Health St Mary's Hospital - St Louis and SSM St Clare Health Center. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does John G. Mellas see patients?
- Medicare's clinician data lists 3 practice locations, including Saint Louis, MO and Fenton, MO. Call before your visit to confirm the address.
- What is John G. Mellas's specialty?
- Medicare lists Nephrology as the primary specialty, and also Internal Medicine.
- Does John G. Mellas accept Medicare assignment?
- Yes. Medicare's clinician data says John G. Mellas 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 John G. Mellas?
- (314) 842-9669, as listed in official Medicare / NPI Registry data.
- What is John G. Mellas's NPI number?
- 1497712079. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where John G. Mellas works
Medicare's Facility Affiliation Data lists John G. Mellas at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Missouri Baptist Medical CenterSaint Louis, MO · Acute Care Hospital · CCN 260108
- Northwestern Medicine Central Dupage HospitalWinfield, IL · Acute Care Hospital · CCN 140242
- SSM Health St Mary's Hospital - St LouisSaint Louis, MO · Acute Care Hospital · CCN 260091
- SSM St Clare Health CenterFenton, MO · Acute Care Hospital · CCN 260081
Practice locations
Addresses where John G. Mellas is enrolled with Medicare (CMS data updated 2026-10-02).
- 10004 Kennerly Rd, Suite 374bSaint Louis, MO 63128 (314) 842‑9669
- 1015 Bowles AveFenton, MO 63026 (636) 496‑2000
- 450 N New Ballas Rd, Suite 204Saint Louis, MO 63141 (314) 991‑0137
Group practices
Medicare enrollment lists John G. Mellas as a member of this group (CMS data updated 2026-10-02).
- Nephrology and Hypertension Specialists LLC8 clinicians in the group
Specialties
- Nephrologyprimary
- Internal Medicinealso
Other nephrologists 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 Illinois College Of Med (chi/peor/rock/chm-Urb) |
| Graduation year | 1977 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1497712079 |
| 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