Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

William L Horvath, MD

Hematology & Oncology Physician in Sylvania, OH · enumerated 2005.

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

National Provider Identifier

1023015351

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Registry record

Entity type Individual (Type 1)

Name William L Horvath

Credential MD

Sex Male

Practice address 5308 Harroun Rd, Suite 055, Sylvania, OH, 43560

Phone (419) 824-6599

Fax (419) 885-3870

Enumeration date Jul 1, 2005

Last updated in NPPES May 1, 2012

Taxonomy & licenses

207RH0003X Hematology & Oncology Physician Allopathic & Osteopathic Physicians · License 35038120 (OH) Primary

207RH0003X Hematology & Oncology Physician Allopathic & Osteopathic Physicians · License 4301058940 (MI) Secondary

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
H00419406	Other	OH	MEDICARE
P00934620	Other	OH	RRMC
0294079	Medicaid	OH	-

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.

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Frequently asked questions

Where does William Horvath practice?

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

What is the NPI number for William Horvath?

The National Provider Identifier (NPI) for William Horvath is 1023015351, a Type 1 (individual) record in the CMS NPPES registry.

Other providers at this practice address

Browse all →

Jeffrey Muler Hematology & Oncology Physician · Sylvania, OH NPI 1285631739 Kenneth Krupp Hematology & Oncology Physician · Sylvania, OH NPI 1508863747 George Pipoly Hematology & Oncology Physician · Sylvania, OH NPI 1689671919 Sarah Puckett Obstetrics & Gynecology Physician · Sylvania, OH NPI 1831199421 A David James Internal Medicine Physician · Sylvania, OH NPI 1770585663 Terry Gibbs Obstetrics & Gynecology Physician · Sylvania, OH NPI 1457353237 Promedica Central Physicians Obstetrics & Gynecology Physician · Sylvania, OH NPI 1407996333 Kimberly Bruhl Hematology & Oncology Physician · Sylvania, OH NPI 1609053602

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2012-05-01.