Guillermo Ares, MD
Guillermo Ares, MD is a Pediatric Surgery Physician in Maywood, IL, registered under NPI 1942542105. 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 2160 S 1ST AVE, Maywood, IL 60153. 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 |
|---|---|---|
| 036139625 | IL | Pediatric Surgery Physician primary |
This provider holds licence 036139625 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 - General Surgery
- PAC ID
- 0143521591
- Enrollment ID
- I20221024001443
Medicare enrolment is recorded as approved under the provider type Practitioner - General Surgery. 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 Pediatric Surgery covers
A surgeon with expertise in the management of surgical conditions in premature and newborn infants, children and adolescents. NUCC Health Care Provider Taxonomy, code 2086S0120X
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 | |
|---|---|---|---|---|
| 2086S0120X | Pediatric Surgery Physician Pediatric Surgery | 036139625 | IL | primary |
| 390200000X | Student in an Organized Health Care Education/Training Program | — | — |
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 | 1942542105 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 25, 2013 |
| Last updated | Oct 14, 2022 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
2160 S 1ST AVE Maywood, IL 60153 (708) 216-9000 |
| Mailing address |
833 W 15TH PL UNIT 415 Chicago, IL 60608 |
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 | 9 | 4 | 2 | 5 | 4 | 2 | 1 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 9 | 8 | 2 | 1 | 4 | 4 | 1 | 0 |
Sum = 55 · next multiple of 10 = 60 · check digit = 5 · actual last digit = 5
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.