John F. Warren, MD
Ophthalmology Physician · Greenfield, MA
John F. Warren, MD is an ophthalmology physician with a practice address in Greenfield, Massachusetts, and NPI 1386634400, issued on Oct 28, 2005. Check the license (Massachusetts 223233, as entered in NPPES) on the Massachusetts Board of Registration in Medicine; the Medicare figures below come from public CMS files.
- Name
- John F. Warren
- Credential
- MD
- Primary taxonomy
- Ophthalmology Physician 207W00000X
- License number
- 223233 MA
Self-reported in NPPES; status is on the state search - Practice location
- 33 Riddell St, Greenfield, MA 01301
- Phone
- (413) 774-7016
- Enumerated
- Oct 28, 2005
- Record last updated
- Mar 7, 2023
- Fax
- (413) 773-7596
- Medicare enrollment
- Enrolled (PECOS I20050223000612); accepts Medicare assignment
- Medical or professional school
- Stanford University School Of Medicine, 1997
- Entity
- Type 1 · individual
8 nearest ophthalmology physician records → All 791 in Massachusetts → Look up another NPI →
Also registered at 33 Riddell St
A shared address usually means a shared clinic or building; it does not show who employs whom.
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- Raymond Colbert, M.D.Geriatric Medicine (Internal Medicine) Physician1649237199
- Thomas Echeverria, MDSpecialist1255487534
- Margaret Ferry, MDEndocrinology, Diabetes & Metabolism Physician1457454894
- Steven Geller, DMDPeriodontics1841303278
Verify John F. Warren in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMassachusetts Board of Registration in Medicine
Search for license 223233Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
78% more Medicare Part D claims than the average ophthalmology physician in 2024
2,695 Medicare Part D claims for 1,067 beneficiaries, against an average of 1,518 among the 16,459 providers of this specialty who prescribed in Part D.
Most prescribed
- Ketorolac Tromethamine1,339 claims
- Prednisolone Acetate513 claims
- Latanoprost212 claims
- Brimonidine Tartrate94 claims
- Timolol Maleate56 claims
- Dorzolamide-Timolol53 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.
The practice group's MIPS final score for 2023 (Medicare payment program): 97.2 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $1,237.23
23 payments; by number, the most common kind was food and beverage; the largest payer was Harrow Eye, LLC. The 13,221 providers of this specialty with any payment received $4,535.02 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Bills Medicare through one group practice
- Longwood Eye LLCWest Springfield, MA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
John F. Warren among 791 ophthalmology physician records in Massachusetts
John F. Warren, MD is one of 791 ophthalmology physician records with a practice address in Massachusetts. 76% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 77% newer
- In a Medicare fileYes · 76% of these records are
- In the CMS Doctors and Clinicians fileYes · 65% of these records are
- Graduated1997 · median 2002 among the 518 with a school on file
- Record last updated2023 · 65% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207W00000X and a Massachusetts practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Ophthalmology Physician providers in Massachusetts
There are 791 ophthalmology physician records in Massachusetts.
All 791 in Massachusetts → Every provider in Greenfield → Ophthalmology Physician nationwide →
The 8 ophthalmology physician records with the nearest ZIP codes
- Robert Austin, M.D.Greenfield, MA 013011013942002
- Pierre Alfred, MDAthol, MA 013311912998501
- Andrew Danyluk, MDWilliamstown, MA 012671003816695
- Estela Ogiste, MD, PHDNorth Adams, MA 012471780684902
- Joseph Gold, M.D.Great Barrington, MA 012301649243809
- Stephen Moore, MDGt Barrington, MA 012301649384793
- Diane Singer, M.D.Great Barrington, MA 012301275554826
- Neal Ginsberg, M.D.Pittsfield, MA 012011801839287
Common questions
What is John F. Warren, MD's NPI number?
John F. Warren, MD's National Provider Identifier (NPI) is 1386634400, issued on Oct 28, 2005. An NPI identifies a provider in billing; it is not a license.
Where is John F. Warren, MD located?
The NPPES record lists a practice address at 33 Riddell St, Greenfield, MA, 01301. Phone: (413) 774-7016. Providers update this record themselves, so call before visiting.
How can I verify John F. Warren, MD's license?
NPPES lists Massachusetts license number 223233, as entered by the provider. Search the Massachusetts Board of Registration in Medicine at https://findmydoctor.mass.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does John F. Warren, MD prescribe under Medicare Part D?
In 2024, John F. Warren, MD had 2,695 Medicare Part D claims for 1,067 beneficiaries; the average among ophthalmology physician prescribers was 1,518. Part D covers Medicare prescriptions only.
What is John F. Warren, MD's MIPS final score?
The 2023 MIPS final score is 97.2 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
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.