Joseph Chang, MD
Gastroenterology · Denver, CONPI 1417968256
Payments from drug & device makers
What this record shows
This record is dominated by speaking fees: $8,100 of the $10,314 with a category attached, or 78.5%. AbbVie accounts for 91.4% of it on its own, with 9 other manufacturers making up the rest. Reporting peaked in 2019 at $9,864 and has fallen 98.3% since, to $169 in 2025.
Across 63 payments — averaging $163.71 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- AbbVie$9K
- Phathom Pharmaceuticals, Inc.$251
- Pfizer$185
- Covidien LP$171
- Ironwood Pharmaceuticals, Inc$109
- Takeda Pharmaceuticals U.S.A., Inc.$59
- plus $114 from 4 others
What the payments were for
- Speaking & faculty fees$8,10079%
- Travel & lodging$8799%
- Food & beverage$1,32713%
- Education$80%
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) | 37 | $9,425 |
| Phathom Pharmaceuticals, Inc. | 3 | $251 |
| Pfizer | 11 | $185 |
| Covidien LP | 2 | $171 |
| Ironwood Pharmaceuticals, Inc | 2 | $109 |
| Takeda Pharmaceuticals U.S.A., Inc. | 3 | $59 |
| Braintree Laboratories, Inc. | 1 | $35 |
| Intercept Pharmaceuticals, Inc. | 2 | $32 |
| Olympus America Inc. | 1 | $24 |
| Johnson & Johnson | 1 | $23 |
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
$10,314 in reported general payments places this provider in the 80th percentile of 304 gastroenterology providers in Colorado.
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 |
|---|---|---|
| Pantoprazole Sodium | 32 | $683 |
| Esomeprazole Magnesium | 14 | $670 |
| Omeprazole | 11 | $115 |
Paid to pharmacies, not to this prescriber.
Other gastroenterology in Denver
- Mary Ann HuangDenver$408K
- Pranav PeriyalwarDenver$180K
- Jonathon FishmanDenver$92K
- Stephen NewDenver$16K
- Kevin SiejaDenver$10K
- Daniel SiegelDenver$8K
- Peter McNallyFt Carson$1.1M
- Douglas AdlerColorado Springs$910K
- Marcelo KugelmasEnglewood$660K
- Gareth WeinerThornton$382K
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.