Melissa Tonn, MD
Melissa Tonn, MD is a Preventive Medicine/Occupational Environmental Medicine Physician in Dallas, TX, registered under NPI 1366493322. 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 8117 PRESTON RD SUITE 530, Dallas, TX 75225. 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 |
|---|---|---|
| H2840 | TX | Preventive Medicine/Occupational… primary |
This provider holds licence H2840 issued in TX. 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 Preventive Medicine/Occupational Environmental Medicine covers
A preventive medicine physician who specializes in preventive medicine/occupational-environmental medicine, which is focused on protecting the population from occupational and environmental conditions. NUCC Health Care Provider Taxonomy, code 2083P0500X
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 | 1366493322 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | May 15, 2006 |
| Last updated | Jul 8, 2007 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | MD |
| Practice address |
8117 PRESTON RD SUITE 530 Dallas, TX 75225 (214) 691-2977 Fax (214) 691-7955 |
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 | 3 | 6 | 6 | 4 | 9 | 3 | 3 | 2 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 3 | 3 | 6 | 8 | 9 | 6 | 3 | 4 |
Sum = 68 · next multiple of 10 = 70 · check digit = 2 · actual last digit = 2
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.