David Guan, M.D.
David Guan, M.D. is a Pulmonary Disease Physician in Chattanooga, TN, registered under NPI 1891772208. 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 1814 MCCALLIE AVE, Chattanooga, TN 37404. 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 |
|---|---|---|
| 35362 | TN | Pulmonary Disease Physician primary |
| 056561 | GA | Critical Care Medicine (Internal… |
| 3065 | WI | Critical Care Medicine (Internal… |
| 22557 | NH | Pulmonary Disease Physician |
| 3065 | WI | Pulmonary Disease Physician |
| 35362 | TN | Sleep Medicine (Internal Medicine)… |
Licences are recorded in 4 states: TN, GA, WI, NH. 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
- 8426044454
Enrolled in Medicare 3 times, across 3 states:
| State | Enrollment ID | Provider type |
|---|---|---|
| Tennessee | I20040423000638 | Practitioner - Pulmonary Disease |
| Wisconsin | I20230712002487 | Practitioner - Critical Care (intensivists) |
| Michigan | I20250212003372 | Practitioner - Internal Medicine |
Medicare enrolment is recorded as approved under the provider type Practitioner - Pulmonary Disease. There are 3 separate enrolment records across 3 states (TN, WI, MI). Multiple enrolments usually mean the provider bills Medicare from more than one practice location, or has kept an earlier enrolment after moving. Each record carries its own enrolment ID, listed above. 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.
Licensed in 4 states
This provider holds licences in 4 states: Georgia, New Hampshire, Tennessee and Wisconsin. The practice address on file is in Chattanooga, TN, 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
- 35362
- Specialty
- Pulmonary 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 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 6 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 | 35362 | TN | primary |
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | 056561 | GA | |
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | 3065 | WI | |
| 207RP1001X | Pulmonary Disease Physician Pulmonary Disease | 22557 | NH | |
| 207RP1001X | Pulmonary Disease Physician Pulmonary Disease | 3065 | WI | |
| 207RS0012X | Sleep Medicine (Internal Medicine) Physician Sleep Medicine | 35362 | TN |
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 | 1891772208 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Dec 28, 2005 |
| Last updated | Jun 7, 2023 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
1814 MCCALLIE AVE Chattanooga, TN 37404 (423) 208-9030 Fax (800) 875-1815 |
| Other identifiers |
1891772208
· Medicaid (TN) |
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 | 8 | 9 | 1 | 7 | 7 | 2 | 2 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 9 | 1 | 5 | 7 | 4 | 2 | 0 |
Sum = 62 · next multiple of 10 = 70 · 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.