Nathan Nowalk, M.D.
Nathan Nowalk, M.D. is a Pulmonary Disease Physician in Chicago, IL, registered under NPI 1003298720. 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 5841 S MARYLAND AVE, Chicago, IL 60637. 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 |
|---|---|---|
| 036152140 | IL | Pulmonary Disease Physician primary |
| MD490543 | PA | Sleep Medicine (Internal Medicine)… |
| 036152140 | IL | Critical Care Medicine (Internal… |
Licences are recorded in 2 states: IL, PA. Providers licensed in several states often practise near a state border or deliver telehealth across state lines.
- Status
- Approved
- Provider type
- Practitioner - Pulmonary Disease
- PAC ID
- 8224373873
Medicare enrolment is recorded as approved under the provider type Practitioner - Pulmonary Disease. 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 Pennsylvania. 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
- 036152140
- Specialty
- Pulmonary Disease Physician
- Licence
- MD490543
- Specialty
- Sleep Medicine (Internal Medicine)…
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 Pulmonary Disease covers
An internist who treats diseases of the lungs and airways. The pulmonologist diagnoses and treats cancer, pneumonia, pleurisy, asthma, occupational and environmental diseases, bronchitis, sleep disorders, emphysema and other complex disorders of the lungs. NUCC Health Care Provider Taxonomy, code 207RP1001X
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 | |
|---|---|---|---|---|
| 207RP1001X | Pulmonary Disease Physician Pulmonary Disease | 036152140 | IL | primary |
| 207RS0012X | Sleep Medicine (Internal Medicine) Physician Sleep Medicine | MD490543 | PA | |
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | 036152140 | 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 | 1003298720 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jun 18, 2015 |
| Last updated | Sep 10, 2025 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
5841 S MARYLAND AVE Chicago, IL 60637 (888) 824-0200 |
| Mailing address |
150 HARVESTER DR STE 300 Burr Ridge, IL 60527 |
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 | 2 | 9 | 8 | 7 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 0 | 0 | 3 | 4 | 9 | 7 | 7 | 4 |
Sum = 60 · next multiple of 10 = 60 · check digit = 0 · actual last digit = 0
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.