Thomas Chang
Foot & Ankle Surgery · Santa Rosa, CANPI 1841315736
Payments from drug & device makers
What this record shows
This record is dominated by royalties or licence payments: $1,452,453 of the $2,030,400 with a category attached, or 71.5%. 35 manufacturers reported payments, led by Paragon 28, Inc. at 57.7% of the total. Reporting peaked in 2021 at $471,124 and has fallen 95.1% since, to $23,092 in 2025. Among foot & ankle surgery 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 456 payments — averaging $4452.63 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Paragon 28, Inc.$1.2M
- Depuy Synthes Products, Inc.$599K
- Ossio Inc$91K
- Stryker$53K
- Bioventus LLC$40K
- Crossroads Extremity Systems, LLC$27K
- plus $50K from 29 others
Across 9 payments — averaging $1028.69 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.
- Paragon 28, Inc.$9K
Across 9 payments — averaging $8888.89 each. An ownership or investment interest held by the physician or an immediate family member.
- Ossio LTD$80K
- Paragon 28, Inc.$0
What the payments were for
- Royalty or licence$1,452,45372%
- Consulting fees$476,37523%
- Speaking & faculty fees$34,4942%
- Travel & lodging$44,9412%
- Food & beverage$20,9031%
- Education$1,2350%
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 |
|---|---|---|
| Paragon 28, Inc. | 154 | $1,171,724 |
| Depuy Synthes Products, Inc. | 23 | $598,733 |
| Ossio Inc | 33 | $90,508 |
| Stryker(2 entities) | 61 | $52,814 |
| Bioventus LLC | 42 | $39,600 |
| Crossroads Extremity Systems, LLC | 30 | $27,007 |
| Johnson & Johnson(2 entities) | 25 | $23,449 |
| Medical Device Business Services, Inc. | 21 | $19,599 |
| Musculoskeletal Transplant Foundation Inc. | 11 | $1,438 |
| Evolution Surgical, Inc | 5 | $1,334 |
| Activortho, Inc. | 1 | $550 |
| Treace Medical Concepts, Inc. | 4 | $497 |
| Abbott | 3 | $363 |
| Zimmer Biomet | 8 | $281 |
| International Life Sciences | 1 | $268 |
| Osiris Therapeutics Inc. | 2 | $239 |
| Smith+Nephew | 4 | $231 |
| Nevro Corp. | 2 | $201 |
| Alafair Biosciences, Inc. | 2 | $177 |
| Integra Lifesciences Corporation | 3 | $169 |
| Mimedx Group, Inc. | 3 | $169 |
| Tactile Systems Technology Inc | 1 | $157 |
| Encore Medical, LP | 1 | $144 |
| Derma Sciences, Inc. | 4 | $118 |
| Carbofix Orthopedics Inc | 1 | $111 |
| Melinta Therapeutics, LLC | 1 | $108 |
| Lifenet Health | 1 | $101 |
| Trimed, Inc. | 1 | $84 |
| Axogen | 1 | $69 |
| Convatec Inc. | 2 | $31 |
| Vertex | 1 | $30 |
| Orthofix Medical, Inc. | 1 | $29 |
| Organogenesis Inc. | 1 | $24 |
| Curonix LLC | 1 | $24 |
| Electronic Waveform Lab, Inc. | 1 | $19 |
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.
- Product Portfolio$507,542
- Portfolio$146,586
- HAMMERLOCK$54,840
- VARIAX$37,732
- Exogen Ultrasound Bone Healing System$29,495
- STAR$21,505
- MOTOBAND$17,727
- AXSOS$14,358
- Medical Implant$11,064
- ANCHORAGE$10,000
- SONICANCHOR$10,000
- Exogen$8,225
- CARTIVA$6,180
- EASY CLIP$5,000
- APEX 3D$2,760
- ALLOWRAP$2,406
- HOFFMANN$2,052
- APEX3D$782
- APEX$509
- Lapiplasty System$413
How this compares
$2,030,400 in reported general payments places this provider in the 95th percentile of 1,126 foot & ankle surgery 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 |
|---|---|---|
| Hydrocodone-AcetaminophenHydrocodone/Acetaminophen | 108 | $829 |
| Cephalexin | 54 | $427 |
| Terbinafine Hcl | 30 | $339 |
| Gabapentin | 24 | $268 |
| Tramadol Hcl | 26 | $84 |
| Meloxicam | 37 | $78 |
Paid to pharmacies, not to this prescriber.
Other foot & ankle surgery in Santa Rosa
- Walter D CostaSanta Rosa$37K
- Eric GizaSacramento$3.6M
- Thomas HarrisPasadena$3M
- Michael CoughlinSan Francisco$1.6M
- Vladimir ZeetserEncino$677K
- Jason NowakRedding$526K
- Candice BradyCamarillo$462K
- Andrew HsuOrange$456K
- Eric TanLos Angeles$447K
- Joseph ParkBurbank$387K
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.