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 .
- 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
- 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
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
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 Wynnewood Pulmonary Disease Physician, average services per provider: 121. This provider delivers 14× the peer median.Open Payments
Industry payments received
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
Medicare Part D · 2023
Top prescriptions
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
Frequently asked questions
What is Dr. Gerard Diefes's medical specialty?
Dr. Gerard Diefes practices Pulmonary Disease Physician in Wynnewood, PA.
Where does Dr. Gerard Diefes practice?
Dr. Gerard Diefes practices at 1001 City Line Ave, Wynnewood, PA 190963902. Office phone: 6108960280.
What is Dr. Gerard Diefes's NPI?
Dr. Gerard Diefes's National Provider Identifier (NPI) is 1417948951, issued by NPPES.
Does Dr. Gerard Diefes accept Medicare assignment?
Yes. Dr. Gerard Diefes accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Gerard Diefes commonly perform?
Top Medicare-reported procedures in 2023: Subsequent hospital care with moderate levelof medical decision making (HCPCS 99232); Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Established patient office or other outpatient visit (HCPCS 99214). Source: CMS Medicare Physician & Other Practitioners file.