Mark Tsai
Gastroenterology · Northridge, CANPI 1962566950
Payments from drug & device makers
What this record shows
Almost everything reported here is food and beverage — 99.2% of the total across 103 separate payments, which is the pattern of a clinician who attends manufacturer presentations rather than one with a consulting arrangement. It is spread thinly across 22 manufacturers, the largest accounting for just 23.9% — the pattern of someone who eats at a lot of different presentations. Reporting peaked in 2019 at $5,131 and has fallen 99.6% since, to $20 in 2025.
Across 103 payments — averaging $67.81 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- AbbVie$2K
- Amgen$1K
- Amarin Pharma, Inc.$607
- Johnson & Johnson$560
- Salix Pharmaceuticals, A Division Of Bausch Health US, LLC$490
- AstraZeneca$442
- plus $2K from 16 others
What the payments were for
- Food & beverage$6,93199%
- Gifts$531%
Most of this is food and beverage — typically meals provided during product presentations at a clinic or hospital. Nationally that is the single largest category of reported payments by count.
General payments by program year
Who reported the general payments
Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.
| Company | Payments | Total |
|---|---|---|
| AbbVie(2 entities) | 32 | $1,672 |
| Amgen | 12 | $1,397 |
| Amarin Pharma, Inc. | 7 | $607 |
| Johnson & Johnson(2 entities) | 6 | $560 |
| Salix Pharmaceuticals, A Division Of Bausch Health US, LLC | 11 | $490 |
| AstraZeneca | 4 | $442 |
| Gilead | 7 | $279 |
| Pfizer | 2 | $250 |
| Boehringer Ingelheim | 2 | $238 |
| Intercept Pharmaceuticals, Inc. | 2 | $141 |
| E.r. Squibb & Sons, L.L.C. | 1 | $125 |
| Biohaven Pharmaceuticals, Inc. | 1 | $119 |
| Merck | 1 | $118 |
| GSK | 1 | $117 |
| Novo Nordisk | 1 | $92 |
| Braintree Laboratories, Inc. | 2 | $79 |
| Vanda Pharmaceuticals Inc. | 2 | $62 |
| Nestle Healthcare Nutrition Inc. | 3 | $62 |
| Takeda Pharmaceuticals U.S.A., Inc. | 2 | $47 |
| Daiichi Sankyo Inc. | 2 | $46 |
| Bristol Myers Squibb | 1 | $22 |
| Shionogi Inc | 1 | $17 |
What the payments were tied to
Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.
How this compares
$6,984 in reported general payments places this provider in the 75th percentile of 1,885 gastroenterology providers in California.
Other gastroenterology in Northridge
- Bennett RothLos Angeles$2.8M
- Douglas NguyenMission Viejo$2M
- Sammy SaabLos Angeles$1.9M
- Kenneth ChangNewport Beach$1.3M
- Joo HwangStanford$1M
- Drew SchembreWalnut Creek$659K
- Quan Nhula Jolla$641K
- Sadeea AbbasiLos Angeles$556K
- Ali RezaieWest Hollywood$519K
- Kenneth BinmoellerSan Francisco$507K
Where these figures come from
- Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
- Identity: NPPES NPI Registry, July 2026.