Willis Chang, MD
Infectious Disease · Waipahu, HINPI 1558306720
Payments from drug & device makers
What this record shows
Almost everything reported here is food and beverage — 96.0% of the total across 172 separate payments, which is the pattern of a clinician who attends manufacturer presentations rather than one with a consulting arrangement. 12 manufacturers reported payments, led by AbbVie at 57.9% of the total. 2025 is the largest year on record at $1,276, 2.1 times the $600 reported in 2019.
Across 172 payments — averaging $25.61 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- AbbVie$3K
- Insmed, Inc.$696
- Abiomed$295
- Gilead$244
- Pfizer$154
- Cumberland Pharmaceuticals, Inc.$148
- plus $318 from 6 others
What the payments were for
- Consulting fees$1002%
- Food & beverage$4,22896%
- Education$772%
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) | 111 | $2,550 |
| Insmed, Inc. | 30 | $696 |
| Abiomed | 8 | $295 |
| Gilead | 2 | $244 |
| Pfizer | 8 | $154 |
| Cumberland Pharmaceuticals, Inc. | 2 | $148 |
| Johnson & Johnson | 5 | $117 |
| Comsort, Inc | 1 | $100 |
| E.r. Squibb & Sons, L.L.C. | 2 | $43 |
| Indivior Inc. | 1 | $25 |
| Philips North America LLC | 1 | $17 |
| Merck | 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.
How this compares
$4,404 in reported general payments places this provider in the 80th percentile of 28 infectious disease providers in Hawaii.
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 |
|---|---|---|
| BiktarvyBictegrav/Emtricit/Tenofov Ala | 41 | $182,494 |
| GenvoyaElviteg/Cob/Emtri/Tenof Alafen | 12 | $46,872 |
| JulucaDolutegravir/Rilpivirine | 11 | $37,091 |
| Darunavir | 22 | $25,125 |
| Rifabutin | 12 | $6,611 |
| Ritonavir | 27 | $4,108 |
| Moxifloxacin Hcl | 11 | $1,942 |
| Ethambutol Hcl | 26 | $1,537 |
| Azithromycin | 14 | $13 |
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 |
|---|---|---|
| GileadBiktarvy, Genvoya | $244 | $229,36653 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 80th percentile of 28 infectious disease providers in Hawaii.
Other infectious disease in Waipahu
- Brian PienHonolulu$19K
- Takashi ShinhaHonolulu$12K
- Francis PienHonolulu$10K
- Heath ChungHonolulu$6K
- Russell WongHonolulu$5K
- James WilliamsWailuku$3K
- Benjamin ThomasHonolulu$3K
- Clayton FosterKailua Kona$3K
- Devin LeeWailuku$3K
- Lorrance MajewskiHonolulu$2K
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.