Dennis S. Riff, M.D.
NPI 1922004662ActiveIndividual· Specialist· Anaheim, CA
Specialist (M.D.) in Anaheim, California, trained at Jefferson Medical College of Thomas Jefferson University (class of 1971). Their prescriptions cost Medicare Part D more than their services did: $1,057,424 for 2,371 claims, against $281,174 paid for services in 2024. Abbvie Inc. was the largest of 19 companies reporting payments in 2025, $2,205 in all, mostly food and beverage.
Overview
| NPI | 1922004662 |
|---|---|
| Status | Active |
| Entity type | Individual |
| Credential | M.D. |
| Sole proprietor | No |
| NPI issued | Jun 27, 2005 |
| Last updated in NPPES | Jan 14, 2013 |
Specialties and licenses
| Taxonomy | Code | License | State |
|---|---|---|---|
| Specialist Primary | 174400000X | G22807 | CA |
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 (CA) |
|---|---|
| Accepts assignment | Yes (participating) |
Medicare services in 2024
| Medicare patients | 410 |
|---|---|
| Services billed | 13,160 across 39 procedure codes |
| Paid by Medicare | $281,174 |
Part D prescriptions in 2024
| Prescriptions (claims) | 2,371 · 4,179 30-day fills |
|---|---|
| Patients | 922 |
| Total drug cost | $1,057,424 |
| Generic share | 79% of claims |
Education and affiliations
| Medical school | Jefferson Medical College of Thomas Jefferson University |
|---|---|
| Graduation year | 1971 |
| Medicare specialty | Gastroenterology |
| Secondary specialties | Internal Medicine |
| Telehealth | Offers telehealth |
Medical group
- Associated Gastroenterology Medical GroupAnaheim, CA · 6 clinicians
Hospital affiliations
- Ahmc Anaheim Regional Medical CenterAnaheim, CA
- Uci Health-OrangeOrange, CA
Industry payments (Open Payments)
- 2025$2,205 · 120 payments from 19 companies
- 2024$22,593 · 159 payments from 21 companies
Top paying companies in 2025
| Company | Amount | Payments |
|---|---|---|
| Abbvie Inc. | $558.26 | 43 |
| Ardelyx, Inc. | $299.11 | 14 |
| Pfizer Inc. | $294.97 | 14 |
| Janssen Biotech, Inc. | $183.80 | 11 |
| Salix Pharmaceuticals, A Division of Bausch Health US, LLC | $179.77 | 8 |
What the 2025 payments were for
- Food and Beverage$2,200 · 119 payments
- Travel and Lodging$5.24 · 1 payment
Receiving payments does not imply wrongdoing. What Open Payments covers ·original records
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All 100 Specialist providers in Anaheim · All Specialist providers in California