Teresa O'brien, NP-C
Teresa O'brien, NP-C is an Adult Health Nurse Practitioner in Chicago, IL, registered under NPI 1619356276. 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 1725 W HARRISON ST SUITE 809, Chicago, IL 60612. 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 |
|---|---|---|
| 209.012775 | IL | Adult Health Nurse Practitioner primary |
This provider holds licence 209.012775 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 - Nurse Practitioner
- PAC ID
- 1254645203
- Enrollment ID
- I20150804004689
Medicare enrolment is recorded as approved under the provider type Practitioner - Nurse Practitioner. 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 Adult Health covers
Definition to come... NUCC Health Care Provider Taxonomy, code 363LA2200X
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 | 1619356276 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 28, 2015 |
| Last updated | Aug 3, 2015 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | NP-C |
| Practice address |
1725 W HARRISON ST SUITE 809 Chicago, IL 60612 (312) 942-5904 Fax (312) 942-3192 |
| Mailing address |
1725W HARRISON ST 809 Chicago, IL 60612 |
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 | 6 | 1 | 9 | 3 | 5 | 6 | 2 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 2 | 9 | 6 | 5 | 3 | 2 | 5 |
Sum = 64 · next multiple of 10 = 70 · check digit = 6 · actual last digit = 6
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.