Casey M. O'Brien, PA-C
Physician Assistant · Williston, VT
Casey M. O'Brien, PA-C is a physician assistant with a practice address in Williston, Vermont, and NPI 1073133484, issued on Apr 26, 2020. Check the license (Vermont 055.0031747, as entered in NPPES) with the Vermont board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Casey M. O'Brien
- Credential
- PA-C
- Primary taxonomy
- Physician Assistant 363A00000X
- License number
- 055.0031747 VT
Self-reported in NPPES; status is on the state search - Practice location
- 426 Industrial Ave Ste 130, Williston, VT 05495
- Phone
- (802) 878-1175
- Enumerated
- Apr 26, 2020
- Record last updated
- Jan 13, 2026
- Fax
- (802) 652-5355
- Entity
- Type 1 · individual
8 nearest physician assistant records → All 321 in Vermont → Look up another NPI →
Also registered at 426 Industrial Ave Ste 130
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Lauren Adams, MDFamily Medicine Physician1023695194
- Ashleigh Angle, RDNRegistered Dietitian1073409686
- Alison Huber, RDRegistered Dietitian1760270128
- Michele Lareau, PA-CPhysician Assistant1902037914
- Brianna Siders, RDNutritionist1477179281
- Riley Trowell, RDNRegistered Dietitian1023989159
Verify Casey M. O'Brien in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich Vermont board licenses this profession
Search for license 055.0031747Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
94% fewer Medicare Part D claims than the average physician assistant in 2024
48 Medicare Part D claims for 35 beneficiaries, against an average of 830 among the 101,058 providers of this specialty who prescribed in Part D. Brand-name drugs were 0% of claims.
Most prescribed
- Prednisone17 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
Casey M. O'Brien among 321 physician assistant records in Vermont
Casey M. O'Brien, PA-C is one of 321 physician assistant records with a practice address in Vermont. 74% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2020, is newer than 80% of them.
- NPI issued2020 · 80% of these records are older, 16% newer
- In a Medicare fileYes · 74% of these records are
- In the CMS Doctors and Clinicians fileNo · 65% of these records are
- Record last updated2026 · 59% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 363A00000X and a Vermont practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
11 physician assistant records list a practice address in Williston
They are 11 of the 429 NPPES records with a practice address in Williston, and 321 physician assistant records in Vermont.
All 321 in Vermont → Every provider in Williston → Physician Assistant nationwide →
The 8 physician assistant records with the nearest ZIP codes
- Shannon Burns, PA-C, ATCWilliston, VT 054951366853525
- Richard Dooley, PACWilliston, VT 054951750394979
- Johanna Hauser, PAWilliston, VT 054951366489122
- Patrick Kearney, PAWilliston, VT 054951801868005
- Michele Lareau, PA-CWilliston, VT 054951902037914
- Zachary Nollet, PA-CWilliston, VT 054951417572942
- Michelle TurnerWilliston, VT 054951912769936
- Adrienne Voutila, PA-CWilliston, VT 054951982945036
Common questions
What is Casey M. O'Brien, PA-C's NPI number?
Casey M. O'Brien, PA-C's National Provider Identifier (NPI) is 1073133484, issued on Apr 26, 2020. An NPI identifies a provider in billing; it is not a license.
Where is Casey M. O'Brien, PA-C located?
The NPPES record lists a practice address at 426 Industrial Ave Ste 130, Williston, VT, 05495. Phone: (802) 878-1175. Providers update this record themselves, so call before visiting.
How can I verify Casey M. O'Brien, PA-C's license?
NPPES lists Vermont license number 055.0031747, as entered by the provider. Search the Vermont board that licenses this profession; the NPPES record confirms identity only.
How much does Casey M. O'Brien, PA-C prescribe under Medicare Part D?
In 2024, Casey M. O'Brien, PA-C had 48 Medicare Part D claims for 35 beneficiaries; the average among physician assistant prescribers was 830. Part D covers Medicare prescriptions only.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.