Lin Chang, MD
Gastroenterology · Los Angeles, CANPI 1770518557
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $72,057 of the $79,195 with a category attached, or 91.0%. 16 manufacturers reported payments, led by Ironwood Pharmaceuticals, Inc at 39.7% of the total. Reporting peaked in 2019 at $30,599 and has fallen 73.1% since, to $8,218 in 2025. Among gastroenterology clinicians in CA with any reported payments, this total sits in the top 10% — high for the specialty, which is a reason to read the composition above rather than the number alone.
Across 63 payments — averaging $1257.07 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Ironwood Pharmaceuticals, Inc$31K
- Shire North American Group Inc$13K
- Salix Pharmaceuticals, A Division Of Bausch Health US, LLC$10K
- GSK$8K
- AbbVie$7K
- Eli Lilly$3K
- plus $7K from 10 others
Across 9 payments — averaging $8328.78 each. Payments tied to a research study. These frequently flow through the physician to a hospital or research institution rather than to the physician personally.
- Anx Robotica Corp$47K
- Alnylam Pharmaceuticals Inc.$13K
- Vanda Pharmaceuticals Inc.$8K
- Ardelyx, Inc.$8K
What the payments were for
- Consulting fees$72,05791%
- Speaking & faculty fees$2,4263%
- Travel & lodging$1,1411%
- Food & beverage$3,5675%
- Education$40%
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 |
|---|---|---|
| Ironwood Pharmaceuticals, Inc | 13 | $31,480 |
| Shire North American Group Inc | 2 | $13,399 |
| Salix Pharmaceuticals, A Division Of Bausch Health US, LLC | 20 | $9,965 |
| GSK | 2 | $7,600 |
| AbbVie(2 entities) | 3 | $6,655 |
| Eli Lilly | 3 | $3,384 |
| Ardelyx, Inc. | 7 | $2,999 |
| Takeda Pharmaceuticals U.S.A., Inc. | 1 | $1,540 |
| Mauna Kea Technologies, Inc. | 1 | $1,000 |
| Anx Robotica Corp | 4 | $347 |
| Vibrant Gastro, Inc. | 2 | $274 |
| QOL Medical, LLC | 1 | $208 |
| Boston Scientific | 1 | $161 |
| Madrigal Pharmaceuticals | 1 | $98 |
| Endogastric Solutions, Inc | 1 | $83 |
| Romark Laboratories, LC | 1 | $5 |
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.
- LINZESS$8,491
- XIFAXAN$6,854
- IBSRELA$2,971
- Vibrant Starter Kit$251
- Sucraid$208
- RESOLUTION CLIP$161
- TRULANCE$108
How this compares
$79,195 in reported general payments places this provider in the 90th 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 |
|---|---|---|
| LinzessLinaclotide | 67 | $49,015 |
| MotegrityPrucalopride Succinate | 54 | $29,087 |
| ViberziEluxadoline | 16 | $15,274 |
| SavellaMilnacipran Hcl | 12 | $5,405 |
| Lubiprostone | 21 | $2,240 |
| Desipramine Hcl | 13 | $1,241 |
| Nortriptyline Hcl | 31 | $598 |
| Ondansetron OdtOndansetron | 20 | $566 |
| Oxycodone Hcl | 13 | $348 |
| Venlafaxine Hcl ErVenlafaxine Hcl | 16 | $272 |
| Pregabalin | 16 | $172 |
| Quetiapine Fumarate | 11 | $92 |
| Zolpidem Tartrate | 12 | $31 |
Paid to pharmacies, not to this prescriber.
Companies that both paid and supply prescribed drugs
These companies both reported payments to this provider and make drugs the provider prescribed under Medicare Part D in 2024. For most specialties this overlap is expected — a cardiologist who is paid by a cardiology drugmaker also treats heart disease. It is shown so the reader can see it, not because it implies anything on its own.
| Company | Paid to this provider | Part D cost of their drugs |
|---|---|---|
| AbbVieLinzess, Viberzi, Savella | $6,655 | $69,69395 claims |
| Takeda Pharmaceuticals U.S.A., Inc.Motegrity | $1,540 | $29,08754 claims |
Reading this fairly. The Part D column is what drug plans and patients paid pharmacies — this provider received none of it, and it reflects how many patients they treat and what those drugs cost. Against peers, this provider's reported payments sit in the 90th percentile of 1,885 gastroenterology providers in California.
Other gastroenterology in Los Angeles
- Bennett RothLos Angeles$2.8M
- Sammy SaabLos Angeles$1.9M
- Sadeea AbbasiLos Angeles$556K
- Gil MelmedLos Angeles$467K
- Venkataraman MuthusamyLos Angeles$297K
- Caroline HwangLos Angeles$279K
- Adarsh ThakerLos Angeles$241K
- Andres YarurLos Angeles$218K
- Joseph PisegnaLos Angeles$210K
- Steven-Huy HanLos Angeles$194K
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.