Christopher Sonnenday, MD
Surgery · Ann Arbor, MINPI 1639103740
Payments from drug & device makers
What this record shows
The money is spread across several categories — travel and lodging (45.5%), speaking fees and education — rather than concentrated in one kind of arrangement. 4 manufacturers reported payments, led by Transmedics, Inc. at 45.5% of the total.
Across 7 payments — averaging $866.42 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Transmedics, Inc.$3K
- Sirtex Medical Inc$2K
- Intuitive Surgical$2K
- Organox Ltd$22
Across 19 payments — averaging $3484.85 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.
- Organox Ltd$66K
What the payments were for
- Speaking & faculty fees$1,75029%
- Travel & lodging$2,75745%
- Food & beverage$581%
- Education$1,50025%
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 |
|---|---|---|
| Transmedics, Inc. | 3 | $2,757 |
| Sirtex Medical Inc | 1 | $1,750 |
| Intuitive Surgical | 2 | $1,536 |
| Organox Ltd | 1 | $22 |
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.
- ORGAN CARE SYSTEM$2,757
- SIR-Spheres Microspheres$1,750
- DAVINCI XI$1,500
How this compares
$6,065 in reported general payments places this provider in the 70th percentile of 1,081 surgery providers in Michigan.
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.
Other surgery in Ann Arbor
- Robert BartlettAnn Arbor$859K
- Jenny Shao KashmanianAnn Arbor$80K
- Hope JacksonAnn Arbor$68K
- Anne EhlersAnn Arbor$38K
- Matthew FourmanMonroe$492K
- Bruce McIntoshRochester Hills$435K
- Jon SchramZeeland$261K
- Eric DaviesBrighton$258K
- Robert LyonsYpsilanti$196K
- Joel StrehlTraverse City$170K
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.