Core Diagnostics
Core Diagnostics holds 4 active organization NPIs in the federal registry, with practice locations in 4 cities in 4 states. Each location can bill under its own NPI.
Search the organization with your city to find the NPI for the location you visit or bill.
Find a location's NPIHayward, CA has the most NPIs, 1
Source: CMS NPPES monthly file of Aug 9, 2026, organization NPIs by practice city.
Most NPIs were issued in 2007 and 2010
Source: CMS NPPES, enumeration dates.
1 NPIs were issued in 2007 alone, more than in any other year; none in 12 of the years between.
Hayward, CA locations
The city with the most Core Diagnostics NPIs. The full list of all 4 follows.
| NPI | Location | Primary taxonomy | Issued |
|---|---|---|---|
| 1003128646 | 3535 BREAKWATER AVE, Hayward, CA | Clinical Medical Laboratory | Jul 12, 2010 |
All 4 locations, by state and city
| NPI | Location | Primary taxonomy | Issued |
|---|---|---|---|
| 1003128646 | 3535 BREAKWATER AVE, Hayward, CA | Clinical Medical Laboratory | Jul 12, 2010 |
| 1831850064 | 3831 HOHMAN AVE, Hammond, IN | Family Medicine Physician | Jan 10, 2022 |
| 1467573105 | 1 FRANKLIN AVE, Belleville, NJ | Cardiovascular Disease Physician | Apr 2, 2007 |
| 1891362471 | 1544 SAWDUST RD STE 102, Spring, TX | Sleep Disorder Diagnostic Clinic/Center | Jun 10, 2021 |
Checking an organization
- Match the NPI to the exact location you will visit or bill; each location can have its own.
- Confirm the business entity with the secretary of state.
- Check the HHS-OIG exclusion list for the organization and its owners.
- Verify each clinician you will see on their own record and with the state license search.
Common questions
Why does Core Diagnostics have 4 NPIs?
An organization may obtain more than one Type 2 NPI, for example for separate locations or units that bill on their own. Core Diagnostics's NPIs list practice locations in 4 cities.
Is an organization NPI a license?
No. An NPI identifies who bills. Facilities and the clinicians who work there are licensed separately by the state.
Source: CMS National Plan and Provider Enumeration System (NPPES), monthly file of Aug 9, 2026 (NPPES files on CMS.gov). An NPI identifies who bills; it is not a license.