Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of October 4, 2026.
NPIDirectory

William O Passarelli III, MD

Individual provider Cardiovascular Disease Physician · NPI 1285653113

William O Passarelli III, MD is registered under Cardiovascular Disease (Cardiology) in Pascagoula, Mississippi. Graduated from New York Medical College in 1991, 35 years ago. Practices with Singing River Health System, a 290-clinician group and accepts Medicare assignment. Licensed in Mississippi.

Years since qualifying
35
Trained at
New York Medical College
Licensed in
MS
In the registry since
2006
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

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Practice location Address checks out

4300 Hospital St Ste 102
Pascagoula, MS 39581-5329
Phone: (228) 762-1002
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Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Cardiovascular Disease Physician (primary) Taxonomy 207RC0000X · Licence MS17347 (MS)

Record details

NPI number1285653113
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorYes
NPI enumeratedJuly 19, 2006
Last updated in NPPESJune 28, 2021
Certification dateJune 28, 2021

Medicare enrollment

From the CMS Doctors & Clinicians file — this clinician is enrolled in Medicare.

Medicare specialtyCARDIOVASCULAR DISEASE (CARDIOLOGY)
Also practisesINTERNAL MEDICINE
Medical schoolNEW YORK MEDICAL COLLEGE
Graduated 1991 (35 years in practice)
Group practice Singing River Health System — 290 clinicians
Accepts Medicare assignment Yes — accepts the Medicare-approved amount
Practice locations2 on file with Medicare

Medicare patients and services, 2024

From the CMS Medicare Physician & Other Practitioners file for calendar year 2024. It counts Original Medicare patients only, so a practice that mostly sees Medicare Advantage or privately insured patients looks smaller here than it is.

Medicare patients1,570
Services billed 8,791 a service is one billed item, such as a visit, a test or a procedure
Average patient age76

Dollar amounts are not shown. What Medicare pays a practice is gross billings, before staff, premises and tax and including the cost of any drugs it administers, so it is not what a clinician earns.

Payments from drug and device companies, 2025

Drug and device makers are required by federal law (the Physician Payments Sunshine Act) to report what they pay or give to clinicians, and CMS publishes the reports as Open Payments. This is the 2025 program year. A report is a record of a payment, not an allegation of anything, and many are small items such as meals. Only general payments are listed here; research payments and ownership or investment interests are reported separately by CMS and are not shown.

Food and Beverage $2,277 84 payments · a meal or drink at a meeting or visit, not a fee

Each amount is the sum of what companies reported for that kind of payment in 2025, rounded to the dollar. Not all of it is income to the clinician: a meal is not a fee, a charitable contribution goes to a charity, and a royalty or an acquisition payment is not a salary.

Check a report, or dispute one, at the source in CMS’s own tool, Open Payments. Corrections go through CMS’s dispute process. This site removes a home address on request and asks for no proof, because that is privacy; it will not remove an accurate payment report on request, because that is a statutory public disclosure.

Practises at

Facilities the CMS Facility Affiliation file lists for this clinician. Those with a page here are linked.

Colleagues at Singing River Health System

Clinicians the CMS Doctors & Clinicians file lists under the same group practice. CMS counts 290 clinicians in the practice; 12 are shown here.

Other providers in Pascagoula