Thomas Sak, PSYD
Thomas Sak, PSYD is a provider specialising in Clinical Neuropsychologist in Algonquin, IL, registered under NPI 1073090239. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 1451 MERCHANT DR, Algonquin, IL 60102. 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
NPPES does not list a state licence number for this record. That is not unusual — organizations and some provider types are not required to file one. Verify current licensure with the relevant state board before care.
- Status
- Approved
- Provider type
- Practitioner - Clinical Psychologist
- PAC ID
- 0446771786
- Enrollment ID
- I20250304000746
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.
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 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 103G00000X | Clinical Neuropsychologist | — | — | primary |
| 103T00000X | Psychologist | — | — |
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 | 1073090239 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 20, 2018 |
| Last updated | Sep 23, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | PSYD |
| Practice address |
1451 MERCHANT DR Algonquin, IL 60102 (847) 469-7537 Fax (847) 469-7540 |
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 | 7 | 3 | 0 | 9 | 0 | 2 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 5 | 3 | 0 | 9 | 0 | 2 | 6 |
Sum = 51 · next multiple of 10 = 60 · check digit = 9 · actual last digit = 9
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.