John W. Diefenderfer, D.O.
Family Medicine Physician · Waterville, ME
John W. Diefenderfer, D.O. is a family medicine physician with a practice address in Waterville, Maine, and NPI 1407236185, issued on Jun 8, 2015. Check the license (Maine DO2785, as entered in NPPES) on the Maine Board of Licensure in Medicine; the Medicare figures below come from public CMS files.
- Name
- John W. Diefenderfer
- Credential
- D.O.
- Primary taxonomy
- Family Medicine Physician 207Q00000X
- License numbers
- DO2785 ME
UO 4638 FL
Self-reported in NPPES; status is on the state search - Practice location
- 149 North St, Waterville, ME 04901
- Phone
- (207) 861-5101
- Enumerated
- Jun 8, 2015
- Record last updated
- Jan 20, 2021 (not updated in 5 years: call before relying on the address or phone)
- Fax
- (207) 872-4341
- Medicare enrollment
- Enrolled (PECOS I20190815001786); accepts Medicare assignment
- Entity
- Type 1 · individual
8 nearest family medicine physician records → All 1,172 in Maine → Look up another NPI →
Also registered at 149 North St
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Ahmed Aldilaimi, MDHospitalist Physician1497721849
- Alycia Allen, MSN, NP-CFamily Nurse Practitioner1083046718
- Michael Antoniello, M.D.Emergency Medicine Physician1568470953
- Amethyst Arceo, DOFamily Medicine Physician1801913553
- Timothy Axelson, CRNACertified Registered Nurse Anesthetist1649219353
- Faith Ayepola, MDStudent in an Organized Health Care Education/Training Program1922932417
Verify John W. Diefenderfer in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersMaine Board of Licensure in Medicine
Search for license DO2785Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
99% fewer Medicare Part D claims than the average family medicine physician in 2024
39 Medicare Part D claims, against an average of 3,544 among the 117,163 providers of this specialty who prescribed in Part D. Brand-name drugs were 33% of 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): 79.3 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).
Bills Medicare through one group practice
- Mainegeneral Medical CenterWaterville, ME
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
John W. Diefenderfer among 1,172 family medicine physician records in Maine
John W. Diefenderfer, D.O. is one of 1,172 family medicine physician records with a practice address in Maine. 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 2015, is newer than 74% of them.
- NPI issued2015 · 74% of these records are older, 23% newer
- In a Medicare fileYes · 76% of these records are
- In the CMS Doctors and Clinicians fileYes · 57% of these records are
- Graduated2011 · median 2008 among the 668 with a school on file
- Record last updated2021 · 60% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207Q00000X and a Maine practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
45 family medicine physician records list a practice address in Waterville
They are 45 of the 870 NPPES records with a practice address in Waterville, and 1,172 family medicine physician records in Maine.
All 1,172 in Maine → Every provider in Waterville → Family Medicine Physician nationwide →
The 8 family medicine physician records with the nearest ZIP codes
- Henry Colt, MDWaterville, ME 049011811963929
- James Douglas, DOWaterville, ME 049011760467187
- Raymond Fluke, M.D.Waterville, ME 049011982649968
- Richard Hobbs, MDWaterville, ME 049011164498283
- Catherine Kimball, DOWaterville, ME 049011457356370
- Jeffrey Lovitz, MDWaterville, ME 049011407845704
- Lisa Marrache, MDWaterville, ME 049011124130638
- Julie Phelps, MDWaterville, ME 049011679562979
Common questions
What is John W. Diefenderfer, D.O.'s NPI number?
John W. Diefenderfer, D.O.'s National Provider Identifier (NPI) is 1407236185, issued on Jun 8, 2015. An NPI identifies a provider in billing; it is not a license.
Where is John W. Diefenderfer, D.O. located?
The NPPES record lists a practice address at 149 North St, Waterville, ME, 04901. Phone: (207) 861-5101. Providers update this record themselves, so call before visiting.
How can I verify John W. Diefenderfer, D.O.'s license?
NPPES lists Maine license number DO2785, as entered by the provider. Search the Maine Board of Licensure in Medicine at https://www.maine.gov/md/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does John W. Diefenderfer, D.O. prescribe under Medicare Part D?
In 2024, John W. Diefenderfer, D.O. had 39 Medicare Part D claims; the average among family medicine physician prescribers was 3,544. Part D covers Medicare prescriptions only.
What is John W. Diefenderfer, D.O.'s MIPS final score?
The 2023 MIPS final score is 79.3 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.