William Hornung, M.D.
William Hornung, M.D. is a Critical Care Medicine (Anesthesiology) Physician in Louisville, KY, registered under NPI 1093767618. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty. NPPES records them as a sole proprietor, meaning the practice is not incorporated as a separate legal entity.
Getting there
The practice address on file is 200 ABRAHAM FLEXNER WAY, Louisville, KY 40202. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.
Credentials and Medicare
| Licence | State | Specialty |
|---|---|---|
| 25515 | KY | Critical Care Medicine (Anesthesiology)… primary |
| 25515 | KY | Anesthesiology Physician |
This provider holds licence 25515 issued in KY. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
What Critical Care Medicine covers
An anesthesiologist, who specializes in critical care medicine diagnoses, treats and supports patients with multiple organ dysfunction. This specialist may have administrative responsibilities for intensive care units and may also facilitate and coordinate patient care among the primary physician, the critical care staff and other specialists. NUCC Health Care Provider Taxonomy, code 207LC0200X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207LC0200X | Critical Care Medicine (Anesthesiology) Physician Critical Care Medicine | 25515 | KY | primary |
| 207L00000X | Anesthesiology Physician | 25515 | KY |
The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.
Full NPPES record
An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.
| NPI | 1093767618 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 16, 2006 |
| Last updated | Sep 11, 2025 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
200 ABRAHAM FLEXNER WAY Louisville, KY 40202 (502) 587-4404 Fax (502) 584-0144 |
| Mailing address |
100 E LIBERTY ST SUITE 303 Louisville, KY 40202 |
| Other identifiers |
000000359009
· Other (KY) 64255151 · Medicaid (KY) |
Number check
How the check works, step by step
Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.
| Digit | 8 | 0 | 8 | 4 | 0 | 1 | 0 | 9 | 3 | 7 | 6 | 7 | 6 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 9 | 3 | 5 | 6 | 5 | 6 | 2 |
Sum = 62 · next multiple of 10 = 70 · check digit = 8 · actual last digit = 8
A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.