Gregory Brennan, M.D.
Gregory Brennan, M.D. is a Gastroenterology Physician in Mansfield, TX, registered under NPI 1689017105. 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 647 N MILLER RD STE B, Mansfield, TX 76063. 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 |
|---|---|---|
| Q4044 | TX | Gastroenterology Physician primary |
This provider holds licence Q4044 issued in TX. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.
- Status
- Approved
- Provider type
- Practitioner - Gastroenterology
- PAC ID
- 2466737259
Medicare enrolment is recorded as approved under the provider type Practitioner - Gastroenterology. This means the provider is enrolled to bill Medicare, though it does not tell you whether they are currently accepting new Medicare patients. Call the office to confirm.
What Gastroenterology covers
An internist who specializes in diagnosis and treatment of diseases of the digestive organs including the stomach, bowels, liver and gallbladder. This specialist treats conditions such as abdominal pain, ulcers, diarrhea, cancer and jaundice and performs complex diagnostic and therapeutic procedures using endoscopes to visualize internal organs. NUCC Health Care Provider Taxonomy, code 207RG0100X
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 | 1689017105 valid check digit |
|---|---|
| Entity type | Individual (NPI-1) |
| Enumeration date | Apr 15, 2013 |
| Last updated | Aug 25, 2021 |
| Status | Active |
| Sole proprietor | Yes |
| Credential | M.D. |
| Practice address |
647 N MILLER RD STE B Mansfield, TX 76063 (817) 760-7969 Fax (817) 760-7976 |
| Mailing address |
PO BOX 35629 Dallas, TX 75235 |
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 | 8 | 9 | 0 | 1 | 7 | 1 | 0 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubled? | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 | — | ×2 |
| Value | 8 | 0 | 8 | 8 | 0 | 2 | 6 | 7 | 9 | 0 | 1 | 5 | 1 | 0 |
Sum = 55 · next multiple of 10 = 60 · check digit = 5 · actual last digit = 5
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.