Mark Chang, MD
Orthopaedic Surgery · Munster, INNPI 1871607507
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $136,800 of the $141,381 with a category attached, or 96.8%. Medyssey USA, Inc accounts for 96.8% of it on its own, with 13 other manufacturers making up the rest. Reporting peaked in 2024 at $32,717 and has fallen 50.0% since, to $16,353 in 2025. Among orthopaedic surgery clinicians in IN with any reported payments, this total sits in the top 10% — high for the specialty, which is a reason to read the composition above rather than the number alone.
Across 128 payments — averaging $1104.54 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Medyssey USA, Inc$137K
- Abbott$2K
- Wenzel Spine, Inc.$1K
- Arteriocyte Medical Systems, Inc.$532
- Alphatec Spine, Inc$182
- Stryker$127
- plus $499 from 8 others
What the payments were for
- Consulting fees$136,80097%
- Travel & lodging$1,0351%
- Food & beverage$3,5463%
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 |
|---|---|---|
| Medyssey USA, Inc | 7 | $136,800 |
| Abbott | 74 | $1,866 |
| Wenzel Spine, Inc. | 12 | $1,375 |
| Arteriocyte Medical Systems, Inc. | 6 | $532 |
| Alphatec Spine, Inc | 2 | $182 |
| Stryker | 6 | $127 |
| Medtronic | 4 | $103 |
| Carbofix Spine Inc | 1 | $84 |
| Surgalign Spine Technologies, Inc. | 5 | $84 |
| Globus Medical(2 entities) | 2 | $77 |
| AbbVie | 2 | $56 |
| Carlsmed, Inc. | 1 | $43 |
| Orthofix Medical, Inc. | 5 | $32 |
| Nevro Corp. | 1 | $21 |
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
$141,381 in reported general payments places this provider in the 90th percentile of 400 orthopaedic surgery providers in Indiana.
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 | 880 | $18,740 |
| Oxycodone-AcetaminophenOxycodone Hcl/Acetaminophen | 399 | $18,450 |
| Cyclobenzaprine Hcl | 109 | $2,086 |
| Gabapentin | 193 | $1,915 |
| Morphine Sulfate ErMorphine Sulfate | 47 | $1,658 |
| Tramadol Hcl | 216 | $1,418 |
| Lidocaine | 11 | $1,412 |
| Methylprednisolone | 181 | $1,021 |
| Pregabalin | 39 | $834 |
| Diazepam | 125 | $609 |
| Hydromorphone Hcl | 33 | $606 |
| Oxycodone Hcl | 17 | $509 |
| Ibuprofen | 30 | $298 |
| Tizanidine Hcl | 45 | $246 |
| Alprazolam | 34 | $234 |
Paid to pharmacies, not to this prescriber.
Other orthopaedic surgery in Munster
- Peter ThadaniMunster$316K
- Frank KolisekGreenwood$7.5M
- David FisherIndianapolis$5.9M
- Michael BerendIndianapolis$4M
- John WilliamsFort Wayne$2.7M
- Sanford KunkelIndianapolis$1.9M
- Hill HastingsIndianapolis$1.6M
- Mark KlaassenElkhart$1.3M
- Alan McGeeFort Wayne$1.1M
- Lindsey RolstonNew Castle$1.1M
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.