Registry record
- NPI
- 1659089811
- Profession
- Nurse Practitioner (NP)
- Specialty
- Family Nurse Practitioner (363LF0000X)
- Practice address
- 3900 Joe Ramsey Blvd E Ste 6
Greenville, TX 75401 - Phone
- 9034551100
- In the registry since
- November 7, 2022
- Last NPPES update
- December 8, 2025
- Sole proprietor
- No
- License
- 1098502 (TX)
At this location
One other provider in our data lists 3900 Joe Ramsey Blvd E Ste 6, Greenville as a practice address:
- Maddison Davis, FNP-C
Family Nurse Practitioner · NPI 1912598772
In context
The NPI number of William Mast is 1659089811. They are a Family Nurse Practitioner in Greenville, Texas.
William Mast is one of 55 Family Nurse Practitioners in Greenville and one of 22,499 across Texas in our data.
The NPI has been in the federal registry for 3 years, since November 7, 2022.
Frequently asked questions
What is NPI 1659089811?
NPI 1659089811 is the 10-digit National Provider Identifier assigned to William Mast, a Family Nurse Practitioner practicing in Greenville, Texas. The record has been in the NPPES registry since November 7, 2022.
How do I verify this provider?
Cross-check NPI 1659089811 in the official CMS registry at npiregistry.cms.hhs.gov, and confirm license 1098502 with the TX licensing board. You can also run the number through our free NPI validator to confirm its checksum.
Is this information current?
This profile reflects the June 2026 NPPES data file. NPPES lists the record's last update as December 8, 2025. We refresh our data each month when CMS publishes a new file.
Data: NPPES public registry, June 2026 file. Not medical advice. Verify independently before care or credentialing decisions. Errors in the source record can be corrected at nppes.cms.hhs.gov; see our corrections page.