Gerard John Diefes, M.D.
Pulmonary Disease Physician · Wynnewood, PA
Gerard John Diefes, M.D. is a pulmonary disease physician with a practice address in Wynnewood, Pennsylvania, and NPI 1417948951, issued on Nov 3, 2005. Check the license (Pennsylvania MD056949L, as entered in NPPES) on the Pennsylvania Department of State (PALS); the Medicare figures below come from public CMS files.
- Name
- Gerard John Diefes
- Credential
- M.D.
- Primary taxonomy
- Pulmonary Disease Physician 207RP1001X
- License number
- MD056949L PA
Self-reported in NPPES; status is on the state search - Practice location
- 1001 City Line Ave, Wynnewood, PA 19096
- Phone
- (610) 896-0280
- Enumerated
- Nov 3, 2005
- Record last updated
- May 20, 2025
- Fax
- (610) 896-0286
- Medicaid ID
- 001781333 PA
- Medicare enrollment
- Enrolled (PECOS I20050613000167); accepts Medicare assignment
- Medical or professional school
- Hahnemann University College Of Medicine, 1992
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest pulmonary disease physician records → All 779 in Pennsylvania → Look up another NPI →
Also registered at 1001 City Line Ave
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Gregory Lenchner, M.D.Pulmonary Disease Physician1154302040
- Robert Promisloff, D.O.Pulmonary Disease Physician1487635587
Verify Gerard John Diefes in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersPennsylvania Department of State (PALS)
Search for license MD056949LCheck the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
8% more Medicare Part D claims than the average pulmonary disease physician in 2024
1,545 Medicare Part D claims for 230 beneficiaries, against an average of 1,425 among the 11,596 providers of this specialty who prescribed in Part D. Brand-name drugs were 55% of claims.
Most prescribed
- Albuterol Sulfate Hfa266 claims
- Trelegy Ellipta238 claims
- Prednisone128 claims
- Montelukast Sodium86 claims
- Anoro Ellipta57 claims
- Gabapentin47 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 MIPS final score for 2023 (Medicare payment program): 100 of 100
The Merit-based Incentive Payment System score is reported for this clinician. 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; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $1,227.58
53 payments; by number, the most common kind was food and beverage; the largest payer was GlaxoSmithKline, LLC. The 8,806 providers of this specialty with any payment received $5,159.88 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
- Advocare, LLCChalfont, PA
Source: CMS Doctors and Clinicians National Downloadable File (the group practices a clinician bills Medicare through) (data.cms.gov).
Gerard John Diefes among 779 pulmonary disease physician records in Pennsylvania
Gerard John Diefes, M.D. is one of 779 pulmonary disease physician records with a practice address in Pennsylvania. 86% 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, 89% newer
- In a Medicare fileYes · 86% of these records are
- In the CMS Doctors and Clinicians fileYes · 73% of these records are
- Graduated1992 · median 2003 among the 568 with a school on file
- Record last updated2025 · 61% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 207RP1001X and a Pennsylvania practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
20 pulmonary disease physician records list a practice address in Wynnewood
They are 20 of the 1,246 NPPES records with a practice address in Wynnewood, and 779 pulmonary disease physician records in Pennsylvania.
All 779 in Pennsylvania → Every provider in Wynnewood → Pulmonary Disease Physician nationwide →
The 8 pulmonary disease physician records with the nearest ZIP codes
- William Fineman, M.D.Wynnewood, PA 190961962688564
- Eliot Friedman, MDWynnewood, PA 190961659434165
- Rochelle Goldberg, MDWynnewood, PA 190961649205386
- Lee Greenspon, M.D.Wynnewood, PA 190961164467122
- Susan Gregory, M.D.Wynnewood, PA 190961619913308
- Catherine Kuntz, M.D.Wynnewood, PA 190961669416640
- Leah Lande, MDWynnewood, PA 190961164457602
- Gregory Lenchner, M.D.Wynnewood, PA 190961154302040
Common questions
What is Gerard John Diefes, M.D.'s NPI number?
Gerard John Diefes, M.D.'s National Provider Identifier (NPI) is 1417948951, issued on Nov 3, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Gerard John Diefes, M.D. located?
The NPPES record lists a practice address at 1001 City Line Ave, Wynnewood, PA, 19096. Phone: (610) 896-0280. Providers update this record themselves, so call before visiting.
How can I verify Gerard John Diefes, M.D.'s license?
NPPES lists Pennsylvania license number MD056949L, as entered by the provider. Search the Pennsylvania Department of State (PALS) at https://www.pals.pa.gov/. The NPPES record confirms identity only; the state search shows license status, expiration and public orders.
How much does Gerard John Diefes, M.D. prescribe under Medicare Part D?
In 2024, Gerard John Diefes, M.D. had 1,545 Medicare Part D claims for 230 beneficiaries; the average among pulmonary disease physician prescribers was 1,425. Part D covers Medicare prescriptions only.
What is Gerard John Diefes, M.D.'s MIPS final score?
The 2023 MIPS final score is 100 of 100. 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.