Doctor profile · Federal record

Dr. GERARD DIEFES, M.D.

Pulmonary Disease Physician (CMS: PULMONARY DISEASE) · Critical Care Medicine (Internal Medicine) Physician · Sleep Medicine (Internal Medicine) Physician · WYNNEWOOD, PA

  • NPI 1417948951
  • Accepts Medicare
  • MIPS 92.1 / 100 · 2023
  • 34 yrs in practice
  • Male
  • Group practice
  • No sanctions

Practice & contact

Operates at 2 locations .

NPPES Updated May 11, 2026
Primary practice
1001 CITY LINE AVE, WB 113
WYNNEWOOD, PA 190963902
(610) 896-0280
fax (610) 896-0286
Additional location
736 W Lincoln Hwy
Exton, PA 193412547
(610) 359-5858

Credentials & registration

NPPES · NUCC
NPI registered
November 2005 — 21 yrs on file
Profile last updated
May 20, 2025
Year of graduation
1992 — 34 yrs since
Specialty taxonomy
207RP1001X — NUCC code
State license (1)
Pennsylvania #MD056949L
Medicaid
PA #001781333

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1417948951. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
1,745
Distinct HCPCS
10
Medicare allowed
$191,476
HCPCS Description Services Patients Avg allowed
99232 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 973 163 $83
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 204 93 $125
99214 Established patient office or other outpatient visit, 30-39 minutes 128 80 $134
99291 Critical care, first 30-74 minutes 127 49 $224
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 84 77 $182
99239 Hospital discharge day management, more than 30 minutes 84 73 $120
99222 Initial hospital care with straightforward or low-level medical decision making, if using time, at least 55 minutes 58 56 $137
94727 Test to determine lung volumes using gas dilution or washout 22 21 $47
94729 Test to examine how well the lungs exchange gases 22 21 $61
94010 Test to measure expiratory airflow and volume 18 17 $29

In context: peer comparison

Among 10 peers in this city , average services per provider: 121. This provider delivers 14× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$1,228
Transactions
53
Manufacturers
12
Payer (manufacturer) Industry Txns Amount
GlaxoSmithKline, LLC. 18 $347.62
GENZYME CORPORATION 7 $149.83
AstraZeneca Pharmaceuticals LP 7 $132.97
Regeneron Healthcare Solutions, Inc. 5 $127.35
Mallinckrodt Hospital Products Inc. 5 $107.48
SANOFI-AVENTIS U.S. LLC 1 $99.95
HARMONY BIOSCIENCES LLC 3 $95.79
Insmed, Inc. 3 $81.80
United Therapeutics Corporation 1 $24.60
Paratek Pharmaceuticals, Inc. 1 $22.27
Mylan Specialty L.P. 1 $20.34
JAZZ PHARMACEUTICALS INC. 1 $17.58

By nature of payment

Food and Beverage
$1,128
Education
$100

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
916
Patients
240
Total drug cost
$321,059
Drug Type Claims Patients Total cost
Albuterol Sulfate Hfa (Albuterol Sulfate) Brand 233 56 $8,658
Trelegy Ellipta (Fluticasone/Umeclidin/Vilanter) Brand 203 39 $184,799
Prednisone Generic 110 53 $411
Montelukast Sodium Generic 55 13 $1,042
Breztri Aerosphere (Budesonide/Glycopyr/Formoterol) Brand 42 0 $27,267
Anoro Ellipta (Umeclidinium Brm/Vilanterol Tr) Brand 41 0 $22,583
Symbicort (Budesonide/Formoterol Fumarate) Brand 34 11 $16,935
Stiolto Respimat (Tiotropium Br/Olodaterol Hcl) Brand 29 0 $16,068
Atorvastatin Calcium Generic 28 27 $254
Eliquis (Apixaban) Brand 27 16 $14,532

Hospital affiliations

CMS Hospital Compare