Nicholas Hac, M.D.
Nicholas Hac, M.D. is a Neurology Physician in Chicago, IL, registered under NPI 1144683780. 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 259 E ERIE ST STE 1900, Chicago, IL 60611. 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 |
|---|---|---|
| 036.152380 | IL | Neurology Physician |
| 036152380 | IL | Neurology Physician primary |
This provider holds licence 036.152380 issued in IL. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Neurology
- PAC ID
- 8426394602
- Enrollment ID
- I20200518000419
Medicare enrolment is recorded as approved under the provider type Practitioner - Neurology. Being enrolled means the provider can bill Medicare; it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Neurology covers
A Neurologist specializes in the diagnosis and treatment of diseases or impaired function of the brain, spinal cord, peripheral nerves, muscles, autonomic nervous system, and blood vessels that relate to these structures. NUCC Health Care Provider Taxonomy, code 2084N0400X
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 | |
|---|---|---|---|---|
| 2084N0400X | Neurology Physician Neurology | 036.152380 | IL | |
| 2084N0400X | Neurology Physician Neurology | 036152380 | IL | primary |
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 | 1144683780 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 31, 2016 |
| Last updated | Jul 23, 2020 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Male |
| Credential | M.D. |
| Practice address |
259 E ERIE ST STE 1900 Chicago, IL 60611 (312) 695-7950 |
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 | 1 | 4 | 4 | 6 | 8 | 3 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 1 | 8 | 4 | 3 | 8 | 6 | 7 | 7 |
Sum = 70 · next multiple of 10 = 70 · check digit = 0 · actual last digit = 0
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.