Mark Sitarik, MD
Hematology & Oncology · Boulder, CONPI 1346224664
Payments from drug & device makers
What this record shows
This record is dominated by education: $12 of the $12 with a category attached, or 100.0%. Every reported general payment came from a single manufacturer, Gilead. That places this record below the midpoint for hematology & oncology clinicians in CO, where the typical reported total is $1,826.
Across 1 payment — averaging $11.92 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Gilead$12
Across 1 payment — averaging $4781.25 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.
- E.r. Squibb & Sons, L.L.C.$5K
What the payments were for
- Education$12100%
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 |
|---|---|---|
| Gilead | 1 | $12 |
How this compares
$12 in reported general payments places this provider in the 0th percentile of 169 hematology & oncology providers in Colorado.
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 |
|---|---|---|
| XtandiEnzalutamide | 36 | $510,865 |
| IdhifaEnasidenib Mesylate | 11 | $375,817 |
| PomalystPomalidomide | 11 | $290,242 |
| BraftoviEncorafenib | 14 | $228,437 |
| VerzenioAbemaciclib | 12 | $185,416 |
| CalquenceAcalabrutinib Maleate | 12 | $185,348 |
| GleevecImatinib Mesylate | 13 | $129,010 |
| Imatinib Mesylate | 33 | $93,862 |
| EliquisApixaban | 64 | $66,378 |
| XareltoRivaroxaban | 25 | $38,061 |
| Aprepitant | 13 | $36,006 |
| Anastrozole | 100 | $2,657 |
| Hydroxyurea | 53 | $1,429 |
| Potassium Chloride | 14 | $1,198 |
| Gabapentin | 37 | $981 |
Paid to pharmacies, not to this prescriber.
Other hematology & oncology in Boulder
- David AndorskyBoulder$39K
- Leslie BusbyBoulder$17K
- Amy SchmidtDenver$2.8M
- Yousuf GaffarDenver$963K
- John BurkeAurora$321K
- Manojkumar BupathiLittleton$312K
- Steven SchusterFort Collins$298K
- Douglas ReznickAurora$294K
- Daniel PollyeaAurora$274K
- Robert RifkinDenver$270K
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.