Dr John F Warren, MD - Medicare Ophthalmology in Greenfield, MA

  1. Home
  2. Ophthalmology
  3. MA
  4. Greenfield
Dr John F Warren, MD is a medicare enrolled "Ophthalmology" physician in Greenfield, Massachusetts. He went to Stanford University School Of Medicine and graduated in 1997 and has 27 years of diverse experience with area of expertise as Ophthalmology. He is a member of the group practice Longwood Eye Llc and his current practice location is 33 Riddell St, Greenfield, Massachusetts. You can reach out to his office (for appointments etc.) via phone at (413) 774-7016.

Dr John F Warren is licensed to practice in Massachusetts (license number 223233) and he also participates in the medicare program. He accepts medicare assignments (which means he accepts the Medicare-approved amount; you will not be billed for any more than the Medicare deductible and coinsurance) and his NPI Number is 1386634400.

Contact Information

Dr John F Warren, MD
33 Riddell St,
Greenfield, MA 01301
(413) 774-7016
(413) 773-7596

Map and Direction




Physician's Profile

Full NameDr John F Warren
GenderMale
SpecialityOphthalmology
Experience27 Years
Location33 Riddell St, Greenfield, Massachusetts
Accepts Medicare AssignmentsYes. He accepts the Medicare-approved amount; you will not be billed for any more than the Medicare deductible and coinsurance.
  Medical Education and Training:
  • Dr John F Warren attended and graduated from Stanford University School Of Medicine in 1997
  NPI Data:
  • NPI Number: 1386634400
  • Provider Enumeration Date: 10/28/2005
  • Last Update Date: 03/07/2023
  Medicare PECOS Information:
  • PECOS PAC ID: 8022090075
  • Enrollment ID: I20050223000612

Medical Identifiers

Medical identifiers for Dr John F Warren such as npi, medicare ID, medicare PIN, medicaid, etc.
IdentifierTypeStateIssuer
1386634400NPI-NPPES

Medical Taxonomies and Licenses

TaxonomyTypeLicense (State)Status
207W00000XOphthalmology 223233 (Massachusetts)Primary

Group Practice Association

Group Practice NameGroup PECOS PAC IDNo. of Members
Longwood Eye Llc014363280212

Medicare Reassignments

Some practitioners may not bill the customers directly but medicare billing happens through clinics / group practice / hospitals where the provider works. Medicare reassignment of benefits is a mechanism by which practitioners allow third parties to bill and receive payment for medicare services performed by them. Dr John F Warren allows following entities to bill medicare on his behalf.
Entity NameFranklin Eye Care Associates Llc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1083670574
PECOS PAC ID: 2264336866
Enrollment ID: O20031125000423
Entity NameLongwood Eye Llc
Entity TypePart B Supplier - Clinic/group Practice
Entity IdentifiersNPI Number: 1649875964
PECOS PAC ID: 0143632802
Enrollment ID: O20201222001483

Medicare Part D Prescriber Enrollment

Any physician or other eligible professional who prescribes Part D drugs must either enroll in the Medicare program or opt out in order to prescribe drugs to their patients with Part D prescription drug benefit plans. Dr John F Warren is enrolled with medicare and thus, if eligible, can prescribe medicare part D drugs to patients with medicare part D benefits.

Mailing Address and Practice Location

Mailing AddressPractice Location Address
Dr John F Warren, MD
33 Riddell St,
Greenfield, MA 01301

Ph: (413) 774-7016		Dr John F Warren, MD
33 Riddell St,
Greenfield, MA 01301

Ph: (413) 774-7016

Reviews and Comments


Ophthalmology Doctors in Greenfield, MA

Robert J Austin, M.D.
Ophthalmology
Medicare: Accepting Medicare Assignments
Practice Location: Austin Family Eye Care, 63 French King Highway, Greenfield, MA 01301
Phone: 413-774-3320    
Nathalie Rioux, M.D.
Ophthalmology
Medicare: Accepting Medicare Assignments
Practice Location: Pioneer Valley Ophthalmic Consultants, 489 Bernardston Road, Greenfield, MA 01301
Phone: 413-775-9900    

Medicare Program: Medicare is a federal government program which provides health insurance to people who are 65 or older. This program also covers certain younger people with disabilities (who receive Social Security Disability Insurance - SSDI), and people with End-Stage Renal Disease (permanent kidney failure requiring dialysis or a transplant, sometimes called ESRD.

Medicare Assignment: Assignment means that your doctor, provider, or supplier agrees (or is required by law) to accept the Medicare-approved amount as full payment for covered services. Most doctors, providers, and suppliers accept assignment, but you should always check to make sure. Participating providers have signed an agreement to accept assignment for all Medicare-covered services.

NPI Number: The National Provider Identifier (NPI) is a unique identification number for covered health care providers. The NPI must be used in lieu of legacy provider identifiers in the HIPAA standards transactions. Covered health care providers and all health plans and health care clearinghouses must use the NPIs in the administrative and financial transactions adopted under HIPAA (Health Insurance Portability and Accountability Act).

Our Data: Information on www.medicarelist.com is built using data sources published by Centers for Medicare & Medicaid Services (CMS) under Freedom of Information Act (FOIA). The information disclosed on the NPI Registry are FOIA-disclosable and are required to be disclosed under the FOIA and the eFOIA amendments to the FOIA. There is no way to 'opt out' or 'suppress' the NPPES record data for health care providers with active NPIs.