David B. Leff, DO
NPI 1619956505ActiveIndividual· Internal Medicine, Gastroenterology· Mesa, AZ
Internal Medicine, Gastroenterology (DO) with Arizona Gastrointestinal Associates PLC and 1 other group, practicing in Mesa, Arizona. Their prescriptions cost Medicare Part D more than their services did: $923,722 for 1,235 claims, against $91,130 paid for services in 2024. Genzyme Corporation was the largest of 28 companies reporting payments in 2025, $82,935 in all, mostly speaking and faculty fees. Lists Banner Gateway Medical Center as a hospital affiliation.
Overview
| NPI | 1619956505 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | DO |
| Sole proprietor | No |
| NPI issued | Jan 10, 2006 |
| Last updated in NPPES | Jan 30, 2026 |
| Certified by provider | Jan 30, 2026 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Internal Medicine, Gastroenterology Primary | 207RG0100X | 3220 | AZ |
Exclusion screening
| List | Result | Details |
|---|---|---|
| HHS-OIG LEIE · Nov 10, 2026 | No match | Checked by NPI and by name + state |
| North Carolina Medicaid · Nov 11, 2026 | No match | — |
| New York OMIG · Nov 11, 2026 | No match | — |
| Ohio Medicaid · Nov 11, 2026 | No match | — |
| Pennsylvania Medicheck · Nov 11, 2026 | No match | — |
| Washington HCA · Nov 11, 2026 | No match | — |
Official OIG search · How matching works ·Bulk check a roster
Medicare
| Enrollment (PECOS) | Enrolled Practitioner - Gastroenterology (AZ) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 438 |
|---|---|
| Services billed | 833 across 29 procedure codes |
| Paid by Medicare | $91,130 |
Part D prescriptions in 2024
| Prescriptions (claims) | 1,235 · 2,237 30-day fills |
|---|---|
| Patients | 487 |
| Total drug cost | $923,722 |
| Generic share | 70% of claims |
Education and affiliations
| Graduation year | 1991 |
|---|---|
| Medicare specialty | Gastroenterology |
Medical groups
- Arizona Gastrointestinal Associates PLCScottsdale, AZ · 36 clinicians
- Central Arizona Medical Associates PCMesa, AZ · 12 clinicians
Hospital affiliation
- Banner Gateway Medical CenterGilbert, AZ
Industry payments (Open Payments)
- 2025$82,935 · 249 payments from 28 companies
- 2024$68,865 · 202 payments from 23 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Genzyme Corporation | $32,534 | 30 |
| Abbvie Inc. | $21,859 | 58 |
| Regeneron Healthcare Solutions, Inc. | $18,301 | 24 |
| Aimmune Therapeutics, Inc. | $5,828 | 24 |
| Madrigal Pharmaceuticals | $981.35 | 16 |
What the 2025 payments were for
- Compensation for services other than consulting, including serving as faculty or as a speaker at a venue other than a continuing education program$70,189 · 22 payments
- Food and Beverage$7,569 · 195 payments
- Travel and Lodging$5,178 · 32 payments
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 53 gastroenterologists in Mesa · All gastroenterologists in Arizona