Mark Johnston, MD
Mark Johnston, MD is a Family Medicine Physician in New Rochelle, NY, registered under NPI 1619175460. This provider registers 2 separate taxonomy codes, which usually means they practise across more than one recognised specialty.
Getting there
The practice address on file is WESTCHESTER COUNTY DEPARTMENT OF HEALTH 145 HUGUENOT STREET, New Rochelle, NY 10801. 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 |
|---|---|---|
| 149047 | NY | Family Medicine Physician primary |
| 149047 | NY | Public Health & General Preventive… |
This provider holds licence 149047 issued in NY. 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 Family Medicine covers
Family Medicine is the medical specialty which is concerned with the total health care of the individual and the family. It is the specialty in breadth which integrates the biological, clinical, and behavioral sciences. The scope of family medicine is not limited by age, sex, organ system, or disease entity. NUCC Health Care Provider Taxonomy, code 207Q00000X
All registered taxonomy codes
This provider registers 2 taxonomy codes. The primary code is what appears on most claims; the others record additional recognised specialties.
| Code | Specialty | Licence | State | |
|---|---|---|---|---|
| 207Q00000X | Family Medicine Physician | 149047 | NY | primary |
| 2083P0901X | Public Health & General Preventive Medicine Physician Public Health & General Preventive Medicine | 149047 | NY |
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 | 1619175460 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Jul 3, 2007 |
| Last updated | Apr 24, 2017 |
| Status | Active |
| Sole proprietor | No |
| Credential | MD |
| Practice address |
WESTCHESTER COUNTY DEPARTMENT OF HEALTH 145 HUGUENOT STREET New Rochelle, NY 10801 (914) 813-5237 |
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 | 1 | 9 | 1 | 7 | 5 | 4 | 6 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 2 | 9 | 2 | 7 | 1 | 4 | 3 |
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.