Quick answers
- Which hospitals does William O. Passarelli Iii work at?
- Medicare's official clinician data lists William O. Passarelli Iii at 4 hospitals: Memorial Hospital at Gulfport, Memorial Hospital Biloxi, Singing River Gulfport and Singing River Health System. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does William O. Passarelli Iii see patients?
- Medicare's clinician data lists 3 practice locations, including Pascagoula, MS and Ocean Springs, MS. Call before your visit to confirm the address.
- What is William O. Passarelli Iii's specialty?
- Medicare lists Cardiovascular Disease (Cardiology) as the primary specialty, and also Internal Medicine.
- Does William O. Passarelli Iii accept Medicare assignment?
- Yes. Medicare's clinician data says William O. Passarelli Iii 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 William O. Passarelli Iii?
- (228) 818-0563, as listed in official Medicare / NPI Registry data.
- What is William O. Passarelli Iii's NPI number?
- 1285653113. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where William O. Passarelli Iii works
Medicare's Facility Affiliation Data lists William O. Passarelli Iii at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Memorial Hospital at GulfportGulfport, MS · Acute Care Hospital · CCN 250019
- Memorial Hospital BiloxiBiloxi, MS · Acute Care Hospital · CCN 250007
- Singing River GulfportGulfport, MS · Acute Care Hospital · CCN 250123
- Singing River Health SystemPascagoula, MS · Acute Care Hospital · CCN 250040
Practice locations
Addresses where William O. Passarelli Iii is enrolled with Medicare (CMS data updated 2026-10-02).
- 2809 Denny AvePascagoula, MS 39581 (228) 818‑0563
- 3109 Bienville BlvdOcean Springs, MS 39564 (228) 818‑1111
- 4603 Hospital StPascagoula, MS 39581 (228) 822‑6040
Group practices
Medicare enrollment lists William O. Passarelli Iii as a member of these groups (CMS data updated 2026-10-02).
- Memorial Hospital at Gulfport474 clinicians in the group
- Singing River Health System295 clinicians in the group
Specialties
Find other Cardiovascular Disease (Cardiology) doctors in Mississippi →
Other cardiologists in Pascagoula
Clinicians with the same Medicare primary specialty in Pascagoula, MS — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | New York Medical College |
| Graduation year | 1991 |
| Gender (as listed) | Male |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1285653113 |
| 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