John Chronakos, M.D.
John Chronakos, M.D. is a Pulmonary Disease Physician in Danbury, CT, registered under NPI 1609801273. 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 24 HOSPITAL AVE, Danbury, CT 06810. 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 |
|---|---|---|
| 042126 | CT | Pulmonary Disease Physician primary |
| 042126 | CT | Critical Care Medicine (Internal… |
| 042126 | CT | Sleep Medicine (Internal Medicine)… |
This provider holds licence 042126 issued in CT. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.
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 | 042126 | CT | primary |
| 207RC0200X | Critical Care Medicine (Internal Medicine) Physician Critical Care Medicine | 042126 | CT | |
| 207RS0012X | Sleep Medicine (Internal Medicine) Physician Sleep Medicine | 042126 | CT |
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 | 1609801273 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 12, 2006 |
| Last updated | Jul 31, 2008 |
| Status | Active |
| Sole proprietor | No |
| Credential | M.D. |
| Practice address |
24 HOSPITAL AVE Danbury, CT 06810 (203) 739-7070 Fax (203) 739-8931 |
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 | 0 | 9 | 8 | 0 | 1 | 2 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 0 | 9 | 7 | 0 | 2 | 2 | 5 |
Sum = 57 · next multiple of 10 = 60 · check digit = 3 · actual last digit = 3
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.