Lewis Portnoy, MD
Lewis Portnoy, MD is an Anatomic Pathology & Clinical Pathology Physician in Westport, CT, registered under NPI 1841557949. 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 10 LINDA LN, Westport, CT 06880. 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 |
|---|---|---|
| 12993 | CT | Anatomic Pathology & Clinical Pathology… primary |
This provider holds licence 12993 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 Anatomic Pathology & Clinical Pathology covers
A pathologist deals with the causes and nature of disease and contributes to diagnosis, prognosis and treatment through knowledge gained by the laboratory application of the biologic, chemical and physical sciences. A pathologist uses information gathered from the microscopic examination of tissue specimens, cells and body fluids, and from clinical laboratory tests on body fluids and secretions for the diagnosis, exclusion and monitoring of disease. NUCC Health Care Provider Taxonomy, code 207ZP0102X
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 | 1841557949 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 13, 2012 |
| Last updated | Apr 13, 2012 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
10 LINDA LN Westport, CT 06880 (203) 222-7326 Fax (203) 226-2853 |
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 | 4 | 1 | 5 | 5 | 7 | 9 | 4 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 8 | 8 | 1 | 1 | 5 | 5 | 9 | 8 |
Sum = 71 · next multiple of 10 = 80 · check digit = 9 · actual last digit = 9
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.