Christopher Williams, PH.D.
Christopher Williams, PH.D. is a provider specialising in Clinical Neuropsychologist in Chicago, IL, registered under NPI 1003505967. This provider registers 3 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 2740 W FOSTER AVE STE 113, Chicago, IL 60625. 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 |
|---|---|---|
| 071011013 | IL | Clinical Psychologist |
| 6301019196 | MI | Psychologist |
| 071011013 | IL | Clinical Neuropsychologist primary |
Licences are recorded in 2 states: IL, MI. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Clinical Psychologist
- PAC ID
- 7618322132
- Enrollment ID
- I20231018001068
Medicare enrolment is recorded as approved under the provider type Practitioner - Clinical Psychologist. 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.
Licensed in 2 states
This provider holds licences in 2 states: Illinois and Michigan. The practice address on file is in Chicago, IL, but a licence in another state usually means they see patients there too — either at a second location or by telehealth. If the address above is far from you, it is worth calling to ask whether they practise closer to where you live.
- Licence
- 071011013
- Specialty
- Clinical Psychologist
Licence numbers are self-reported to NPPES at registration. They do not confirm a licence is currently active, in good standing, or valid for the specialty shown — only the state board can tell you that, which is why we link to each one.
What Clinical Neuropsychologist covers
A clinical psychologist who applies principles of assessment and intervention based upon the scientific study of human behavior as it relates to normal and abnormal functioning of the central nervous system. The specialty is dedicated to enhancing the understanding of brain-behavior relationships and the application of such knowledge to human problems. NUCC Health Care Provider Taxonomy, code 103G00000X
All registered taxonomy codes
This provider registers 3 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 103TC0700X | Clinical Psychologist Clinical | 071011013 | IL | |
| 103T00000X | Psychologist | 6301019196 | MI | |
| 103G00000X | Clinical Neuropsychologist | 071011013 | 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 | 1003505967 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 4, 2023 |
| Last updated | Jul 27, 2026 |
| Status | Active |
| Sole proprietor | Yes |
| Gender | Male |
| Credential | PH.D. |
| Practice address |
2740 W FOSTER AVE STE 113 Chicago, IL 60625 (847) 425-6400 Fax (847) 425-6408 |
| Mailing address |
2650 RIDGE AVE STE 1223 Evanston, IL 60201 |
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 | 0 | 3 | 5 | 0 | 5 | 9 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 1 | 0 | 1 | 9 | 3 |
Sum = 43 · next multiple of 10 = 50 · check digit = 7 · actual last digit = 7
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.