Jacek Zajac, MD
Endocrinology, Diabetes & Metabolism · Lombard, ILNPI 1396817912
Payments from drug & device makers
What this record shows
Almost everything reported here is food and beverage — 99.2% of the total across 1,425 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 60 manufacturers, the largest accounting for just 12.0% — the pattern of someone who eats at a lot of different presentations.
Across 1,425 payments — averaging $18.33 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Lilly USA, LLC$3K
- Novo Nordisk$2K
- Mannkind Corporation$2K
- AstraZeneca$2K
- Corcept Therapeutics$1K
- Xeris Pharmaceuticals, Inc.$1K
- plus $14K from 54 others
What the payments were for
- Food & beverage$25,91899%
- Education$1501%
- Gifts$590%
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.
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.
- FARXIGA$647
How this compares
$26,127 in reported general payments places this provider in the 85th percentile of 347 endocrinology, diabetes & metabolism providers in Illinois.
See all endocrinology, diabetes & metabolism providers in Illinois →
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 |
|---|---|---|
| OzempicSemaglutide | 370 | $456,478 |
| TrulicityDulaglutide | 263 | $347,531 |
| JardianceEmpagliflozin | 262 | $286,377 |
| FarxigaDapagliflozin Propanediol | 150 | $140,201 |
| KorlymMifepristone | 14 | $112,947 |
| JanuviaSitagliptin Phosphate | 70 | $79,095 |
| MounjaroTirzepatide | 61 | $75,038 |
| Humulin R U-500Insulin Regular, Human | 16 | $40,817 |
| TymlosAbaloparatide | 13 | $33,210 |
| Toujeo SolostarInsulin Glargine,hum.Rec.Anlog | 40 | $32,341 |
| Humalog Kwikpen U-100Insulin Lispro | 101 | $30,416 |
| Omnipod 5 Dexg7g6 Pods (Gen 5)Insulin Pump Cart,auto,bt,g6/7 | 17 | $26,795 |
| Omnipod Dash Pods (Gen 4)Insulin Pump Cart,cont Inf,bt | 26 | $26,138 |
| Lantus SolostarInsulin Glargine,hum.Rec.Anlog | 170 | $23,633 |
| Fiasp FlextouchInsulin Aspart (Niacinamide) | 27 | $18,953 |
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 |
|---|---|---|
| Novo NordiskOzempic, Rybelsus | $2,163 | $469,887382 claims |
| Lilly USA, LLCTrulicity, Mounjaro, Humalog | $3,133 | $430,078366 claims |
| Boehringer IngelheimJardiance, Synjardy | $1,133 | $289,550273 claims |
| AstraZenecaFarxiga | $1,604 | $140,201150 claims |
| Corcept TherapeuticsKorlym | $1,369 | $112,94714 claims |
| MerckJanuvia | $490 | $79,09570 claims |
| Radius Health, Inc.Tymlos | $537 | $33,21013 claims |
| Amneal Pharmaceuticals LLCLevothyroxine Sodium | $390 | $6,459559 claims |
| Mannkind CorporationAfrezza | $2,100 | $5,07411 claims |
| AbbVieSynthroid | $492 | $3,78965 claims |
| Sanofi-aventis U.S. LLCLantus | $1,046 | $2,50117 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 85th percentile of 347 endocrinology, diabetes & metabolism providers in Illinois.
Other endocrinology, diabetes & metabolism in Lombard
- Terrence SwadeLombard$369K
- Wahid KassarChicago$884K
- Anthony PickLake Forest$665K
- Babak PazookiJoliet$582K
- Ammar BayrakdarEvergreen Park$517K
- George BakrisChicago$403K
- Wenyu HuangChicago$341K
- Liana BillingsSkokie$295K
- Daniel SoArlington Heights$283K
- Silvana PannainChicago$226K
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.