Alexander Tonthat, MD
Gastroenterology · Oroville, CANPI 1124522784
Payments from drug & device makers
What this record shows
Almost everything reported here is food and beverage — 98.3% of the total across 63 separate payments, which is the pattern of a clinician who attends manufacturer presentations rather than one with a consulting arrangement. 10 manufacturers reported payments, led by AbbVie at 37.4% of the total. 2025 is the largest year on record at $916, more than ten times the $12 reported in 2021. That places this record below the midpoint for gastroenterology clinicians in CA, where the typical reported total is $1,790.
Across 63 payments — averaging $18.92 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- AbbVie$446
- Johnson & Johnson$317
- Ipsen Biopharmaceuticals, Inc$125
- Regeneron$125
- Novo Nordisk$49
- Pfizer$38
- plus $93 from 4 others
What the payments were for
- Food & beverage$1,17398%
- Education$202%
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 | 26 | $446 |
| Johnson & Johnson(2 entities) | 21 | $317 |
| Ipsen Biopharmaceuticals, Inc | 6 | $125 |
| Regeneron | 1 | $125 |
| Novo Nordisk | 2 | $49 |
| Pfizer | 2 | $38 |
| Boston Scientific | 2 | $28 |
| Takeda Pharmaceuticals U.S.A., Inc. | 1 | $27 |
| Lilly USA, LLC | 1 | $21 |
| Olympus America Inc. | 1 | $16 |
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.
- DUPIXENT$125
How this compares
$1,192 in reported general payments places this provider in the 40th percentile of 1,885 gastroenterology providers in California.
Medicare billing
What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.
Most prescribed under Part D
| Drug | Claims | Cost to plans & patients |
|---|---|---|
| Esomeprazole Magnesium | 14 | $1,369 |
| Gavilyte-GPeg3350/Sod Sulf,bicarb,cl/Kcl | 67 | $948 |
| Peg-3350 And ElectrolytesPeg3350/Sod Sulf,bicarb,cl/Kcl | 48 | $608 |
| Omeprazole | 30 | $192 |
| Pantoprazole Sodium | 22 | $179 |
| Metoclopramide Hcl | 106 | $102 |
Paid to pharmacies, not to this prescriber.
Other gastroenterology in Oroville
- 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).
- Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
- Identity: NPPES NPI Registry, July 2026.