Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. William James Popovic, MD

Medical Oncology Physician in Shiloh, IL · enumerated 2006 · practices at Protestant Memorial Medical Center, Inc..

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1609824549

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Registry record

Entity type Individual (Type 1)

Name Dr. William James Popovic

Credential MD

Sex Male

Practice address 1418 Cross St, Div Im Medical Oncology, Ste 180, Shiloh, IL, 62269

Phone (618) 607-1340

Fax (618) 622-9724

Enumeration date May 4, 2006

Last updated in NPPES Apr 21, 2025

Taxonomy & licenses

207R00000X Internal Medicine Physician Allopathic & Osteopathic Physicians · License 036060456 (IL) Secondary

207RX0202X Medical Oncology Physician Allopathic & Osteopathic Physicians · License 036060456 (IL) Primary

MD · Doctor of Medicine: A physician who completed medical school (allopathic medicine), residency training, and state licensure. About the MD credential

Other identifiers

Identifier	Type	State	Issuer
200058084	Medicaid	MO	-

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

Read the full guide → Validate an NPI →

Frequently asked questions

Where does William Popovic practice?

The practice location on file with NPPES is in Shiloh, IL. Providers can have multiple locations; NPPES lists the primary practice address.

What is the NPI number for William Popovic?

The National Provider Identifier (NPI) for William Popovic is 1609824549, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

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Susan Laduzinsky Radiation Oncology Physician · Shiloh, IL NPI 1942202155 Alfred Greco Medical Oncology Physician · Shiloh, IL NPI 1073501607 John Visconti Medical Oncology Physician · Shiloh, IL NPI 1033167846 Jason Lee Radiation Oncology Physician · Shiloh, IL NPI 1851618995 Paul Kogan Urology Physician · Shiloh, IL NPI 1023377736 Corey Brooks Physician Assistant · Shiloh, IL NPI 1134466485 Brett Herzog Medical Oncology Physician · Shiloh, IL NPI 1023499282 Christina Wells Family Nurse Practitioner · Shiloh, IL NPI 1699144303

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2025-04-21.