Aaron Grinstein, PA
Physician Assistant · Easthampton, MA
Aaron Grinstein, PA is a physician assistant with a practice address in Easthampton, Massachusetts, and NPI 1457762106, issued on May 15, 2014. Check the license (Massachusetts PA4966, as entered in NPPES) with the Massachusetts board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Aaron Grinstein
- Credential
- PA
- Primary taxonomy
- Physician Assistant 363A00000X
- License numbers
- PA4966 MA
AMD-875 HI
Self-reported in NPPES; status is on the state search - Practice location
- 238 Northampton St, Easthampton, MA 01027
- Phone
- (413) 529-9300
- Enumerated
- May 15, 2014
- Record last updated
- Mar 10, 2025
- Fax
- (866) 644-0870
- Medicare enrollment
- Enrolled (PECOS I20160307002467); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest physician assistant records → All 4,713 in Massachusetts → Look up another NPI →
Also registered at 238 Northampton St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Laura Aierstuck, NPPrimary Care Nurse Practitioner1326690298
- Emma Ash, FNP-BCFamily Nurse Practitioner1336967744
- Elaine Beaudoin, LICSW,LADCClinical Social Worker1205936846
- Elisabeth BorkowskiMedical Physician Assistant1154192854
- Allyson Boucher, PAPhysician Assistant1962147538
Verify Aaron Grinstein in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich Massachusetts board licenses this profession
Search for license PA4966Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
82% fewer Medicare Part D claims than the average physician assistant in 2024
149 Medicare Part D claims for 73 beneficiaries, against an average of 830 among the 101,058 providers of this specialty who prescribed in Part D. Brand-name drugs were 11% of claims.
Most prescribed
- Atorvastatin Calcium13 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.
Bills Medicare through one group practice
- Valley Medical Group PCEasthampton, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Aaron Grinstein among 4,713 physician assistant records in Massachusetts
Aaron Grinstein, PA is one of 4,713 physician assistant records with a practice address in Massachusetts. 78% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2014, is newer than 30% of them.
- NPI issued2014 · 30% of these records are older, 67% newer
- In a Medicare fileYes · 78% of these records are
- In the CMS Doctors and Clinicians fileYes · 68% of these records are
- Graduated2013 · median 2019 among the 3,217 with a school on file
- Record last updated2025 · 38% 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 Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
7 physician assistant records list a practice address in Easthampton
They are 7 of the 426 NPPES records with a practice address in Easthampton, and 4,713 physician assistant records in Massachusetts.
All 4,713 in Massachusetts → Every provider in Easthampton → Physician Assistant nationwide →
The 8 physician assistant records with the nearest ZIP codes
- Allyson Boucher, PAEasthampton, MA 010271962147538
- Heather Clarke, PA-CEasthampton, MA 010271366074122
- Lauren GorskiEasthampton, MA 010271497233977
- Sabrina Kane, PA-CEasthampton, MA 010271598498438
- Trisha Rogers, PA-CEasthampton, MA 010271407198583
- Alexandra West, PAEasthampton, MA 010271366266785
- Raffaele Albano, PAEast Longmeadow, MA 010281679194757
- Sarah Delisle, PAEast Longmeadow, MA 010281386873594
Common questions
What is Aaron Grinstein, PA's NPI number?
Aaron Grinstein, PA's National Provider Identifier (NPI) is 1457762106, issued on May 15, 2014. An NPI identifies a provider in billing; it is not a license.
Where is Aaron Grinstein, PA located?
The NPPES record lists a practice address at 238 Northampton St, Easthampton, MA, 01027. Phone: (413) 529-9300. Providers update this record themselves, so call before visiting.
How can I verify Aaron Grinstein, PA's license?
NPPES lists Massachusetts license number PA4966, as entered by the provider. Search the Massachusetts board that licenses this profession; the NPPES record confirms identity only.
How much does Aaron Grinstein, PA prescribe under Medicare Part D?
In 2024, Aaron Grinstein, PA had 149 Medicare Part D claims for 73 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.