Michael Chang, DO
Pain Medicine · Walnut Creek, CANPI 1205934262
Payments from drug & device makers
What this record shows
Almost everything reported here is food and beverage — 100.0% of the total across 32 separate payments, which is the pattern of a clinician who attends manufacturer presentations rather than one with a consulting arrangement. It is spread thinly across 14 manufacturers, the largest accounting for just 18.3% — the pattern of someone who eats at a lot of different presentations. That places this record below the midpoint for pain medicine clinicians in CA, where the typical reported total is $1,829.
Across 32 payments — averaging $49.38 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Medtronic$290
- Saluda Medical Americas, Inc.$273
- Boston Scientific$220
- Si-bone, Inc.$214
- Vertos Medical, Inc.$150
- Nevro Corp.$139
- plus $294 from 8 others
Across 4 payments — averaging $441.50 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.
- Abbott$2K
- Saluda Medical Americas, Inc.$16
What the payments were for
- Food & beverage$1,580100%
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 |
|---|---|---|
| Medtronic(3 entities) | 7 | $290 |
| Saluda Medical Americas, Inc. | 4 | $273 |
| Boston Scientific | 5 | $220 |
| Si-bone, Inc. | 3 | $214 |
| Vertos Medical, Inc. | 1 | $150 |
| Nevro Corp. | 2 | $139 |
| AstraZeneca | 1 | $122 |
| Bioventus LLC | 3 | $52 |
| SPR Therapeutics, Inc | 1 | $27 |
| Amgen | 1 | $23 |
| Team_makena_llc | 1 | $20 |
| Stryker | 1 | $19 |
| Radius Health, Inc. | 1 | $18 |
| Trevena, Inc. | 1 | $13 |
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.
- mild Device Kit$150
- Intracept$135
- CoreValve Evolut$123
- LOKELMA$122
- Senza$116
- Evoke SCS$102
How this compares
$1,580 in reported general payments places this provider in the 45th percentile of 840 pain 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 |
|---|---|---|
| Baclofen | 146 | $1,010 |
| Gabapentin | 79 | $989 |
| Celecoxib | 22 | $588 |
| Oxycodone-AcetaminophenOxycodone Hcl/Acetaminophen | 11 | $182 |
| Hydrocodone-AcetaminophenHydrocodone/Acetaminophen | 13 | $100 |
| Ibuprofen | 17 | $92 |
| Methylprednisolone | 13 | $56 |
| Tramadol Hcl | 13 | $56 |
| Cyclobenzaprine Hcl | 13 | $50 |
| Diazepam | 32 | $27 |
| Meloxicam | 19 | $18 |
Paid to pharmacies, not to this prescriber.
Other pain medicine in Walnut Creek
- Kasra AmirdelfanWalnut Creek$783K
- Jason PopeSanta Rosa$2.1M
- Ramana NaiduLarkspur$1.4M
- Foead GeulaStudio City$1.3M
- Krishnan ChakravarthyTemecula$1.3M
- Eric GrigsbyNapa$499K
- Jacqueline WeisbeinNapa$494K
- Gerald SacksSanta Monica$389K
- Samir ShethRoseville$356K
- Einar OttestadStanford$352K
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.