Chun Chang, MD
Emergency Medicine · Modesto, CANPI 1003015462
Payments from drug & device makers
What this record shows
This record is dominated by travel and lodging: $1,788 of the $2,867 with a category attached, or 62.3%. Merz North America, Inc. accounts for 86.7% of it on its own, with 6 other manufacturers making up the rest. Reporting peaked in 2023 at $2,595 and has fallen 97.2% since, to $74 in 2025. Among emergency medicine clinicians in CA with any reported payments, this total sits in the top 5% — high for the specialty, which is a reason to read the composition above rather than the number alone.
Across 23 payments — averaging $124.66 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Merz North America, Inc.$2K
- AstraZeneca$117
- Merck$109
- Abbott$101
- Astellas Pharma US Inc$24
- Inari Medical, Inc.$15
- plus $14 from 1 others
What the payments were for
- Travel & lodging$1,78862%
- Food & beverage$1,08038%
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 |
|---|---|---|
| Merz North America, Inc. | 13 | $2,486 |
| AstraZeneca | 1 | $117 |
| Merck | 1 | $109 |
| Abbott | 5 | $101 |
| Astellas Pharma US Inc | 1 | $24 |
| Inari Medical, Inc. | 1 | $15 |
| Stryker | 1 | $14 |
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
$2,867 in reported general payments places this provider in the 95th percentile of 6,006 emergency medicine 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 |
|---|---|---|
| Albuterol Sulfate HfaAlbuterol Sulfate | 28 | $671 |
| Cephalexin | 57 | $547 |
| Ondansetron OdtOndansetron | 54 | $468 |
| Ibuprofen | 93 | $366 |
| Methylprednisolone | 46 | $286 |
| Amoxicillin-Clavulanate PotassAmoxicillin/Potassium Clav | 22 | $267 |
| Doxycycline Hyclate | 15 | $219 |
| Prednisone | 40 | $113 |
| Meclizine Hcl | 24 | $112 |
| Pantoprazole Sodium | 23 | $112 |
| Amoxicillin | 17 | $100 |
| Ciprofloxacin Hcl | 13 | $97 |
| Oxycodone-AcetaminophenOxycodone Hcl/Acetaminophen | 22 | $93 |
| Azithromycin | 20 | $75 |
| Cyclobenzaprine Hcl | 20 | $70 |
Paid to pharmacies, not to this prescriber.
Other emergency medicine in Modesto
- Michael BlueLone Pine$915K
- Andrew AccardiEncinitas$383K
- Fredrick Melik-AbrahamianSylmar$354K
- Graham WalkerStanford$309K
- Douglas WhiteOakland$220K
- Paul PearigenSan Diego$208K
- Richard KozakMission Viejo$203K
- Oron FrenkelSan Francisco$201K
- Matthew KaplanMission Viejo$195K
- John LiboonPoway$188K
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.