Dara Grennan
Dara Grennan is an Infectious Disease Physician in Dixon, IL, registered under NPI 1518282938. This provider registers 3 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is 403 E 1ST ST, Dixon, IL 61021. 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 |
|---|---|---|
| 036-137502 | IL | Infectious Disease Physician primary |
| 036-137502 | IL | Internal Medicine Physician |
| 8153445 | UT | Hospitalist Physician |
| 36.137502 | IL | Hospitalist Physician |
Licences are recorded in 2 states: IL, UT. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Hospitalist
- PAC ID
- 6507092962
Medicare enrolment is recorded as approved under the provider type Practitioner - Hospitalist. This means the provider is enrolled to bill Medicare, though 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 Utah. The practice address on file is in Dixon, 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
- 036-137502
- Specialty
- Infectious Disease Physician
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 Infectious Disease covers
An internist who deals with infectious diseases of all types and in all organ systems. Conditions requiring selective use of antibiotics call for this special skill. This physician often diagnoses and treats AIDS patients and patients with fevers which have not been explained. Infectious disease specialists may also have expertise in preventive medicine and travel medicine. NUCC Health Care Provider Taxonomy, code 207RI0200X
All registered taxonomy codes
This provider registers 4 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207RI0200X | Infectious Disease Physician Infectious Disease | 036-137502 | IL | primary |
| 207R00000X | Internal Medicine Physician | 036-137502 | IL | |
| 208M00000X | Hospitalist Physician | 8153445 | UT | |
| 208M00000X | Hospitalist Physician | 36.137502 | IL |
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 | 1518282938 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Mar 29, 2010 |
| Last updated | Apr 26, 2021 |
| Status | Active |
| Sole proprietor | No |
| Practice address |
403 E 1ST ST Dixon, IL 61021 (815) 285-5629 Fax (815) 285-5634 |
| Mailing address |
680 N LAKE SHORE DR Chicago, IL 60611 |
| Other identifiers |
F400440732
· MEDICARE PTAN (IL) 036137502 (IL) |
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 | 5 | 1 | 8 | 2 | 8 | 2 | 9 | 3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 5 | 2 | 8 | 4 | 8 | 4 | 9 | 6 |
Sum = 72 · next multiple of 10 = 80 · check digit = 8 · actual last digit = 8
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.