Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum
William R Alex, MD
Surgery Physician in Riverside, CA · enumerated 2006.
Data current as of Jul 13, 2026 · sourced from CMS NPPES
National Provider Identifier
1558300681
See something wrong? Report a correction
Registry record
Entity type Individual (Type 1)
Name William R Alex
Credential MD
Sex Male
Practice address 4000 14th St, Ste 306, Riverside, CA, 92501
Phone (951) 682-2036
Fax (951) 682-2942
Enumeration date Jun 5, 2006
Last updated in NPPES Mar 19, 2010
Taxonomy & licenses
2086S0102X Surgical Critical Care Physician Allopathic & Osteopathic Physicians · License G86010 (CA) Secondary
2086S0127X Trauma Surgery Physician Allopathic & Osteopathic Physicians · License G86010 (CA) Secondary
208G00000X Thoracic Surgery (Cardiothoracic Vascular Surgery) Physician Allopathic & Osteopathic Physicians · License G86010 (CA) 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 |
|---|---|---|---|
| 00G860100 | Medicaid | CA | - |
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.
Frequently asked questions
Where does William Alex practice?
The practice location on file with NPPES is in Riverside, CA. Providers can have multiple locations; NPPES lists the primary practice address.
What is the NPI number for William Alex?
The National Provider Identifier (NPI) for William Alex is 1558300681, a Type 1 (individual) record in the CMS NPPES registry.
Other providers at this practice address
Browse all → James Bartley Clinical Genetics (M.D.) Physician · Riverside, CA NPI 1184620411 Ashley Medical Group, Inc Internal Medicine Physician · Riverside, CA NPI 1154327773 Norman Snyder Diagnostic Radiology Physician · Riverside, CA NPI 1316948110 Riverside Imaging LLC Radiology Clinic/Center · Riverside, CA NPI 1104818459 Southern California Transplantation Institute Specialist · Riverside, CA NPI 1164410494 Trinh Tang Internal Medicine Physician · Riverside, CA NPI 1326014986 Donald Blackman Internal Medicine Physician · Riverside, CA NPI 1386687754 William R Alex MD Inc Surgery Physician · Riverside, CA NPI 1184735953
Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2010-03-19.