Gregory Sibley, MD
Radiation Oncology · Fairfax, VANPI 1043211360
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $8,069 of the $10,258 with a category attached, or 78.7%. Novartis accounts for 96.7% of it on its own, with 9 other manufacturers making up the rest. 2025 is the largest year on record at $7,930, more than ten times the $81 reported in 2022. Among radiation oncology clinicians in VA 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 20 payments — averaging $512.89 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Novartis$10K
- Myriad Genetic Laboratories, Inc.$130
- Isoray, Inc$46
- AstraZeneca$34
- Pharmaessentia USA Corporation$28
- Incyte Corporation$24
- plus $77 from 4 others
Across 4 payments — averaging $56,479 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.
- Novartis$226K
What the payments were for
- Consulting fees$8,06979%
- Travel & lodging$1,66116%
- Food & beverage$5285%
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 |
|---|---|---|
| Novartis | 10 | $9,918 |
| Myriad Genetic Laboratories, Inc. | 1 | $130 |
| Isoray, Inc | 2 | $46 |
| AstraZeneca | 1 | $34 |
| Pharmaessentia USA Corporation | 1 | $28 |
| Incyte Corporation | 1 | $24 |
| Bayer | 1 | $23 |
| Johnson & Johnson | 1 | $20 |
| Palette Life Sciences, Inc. | 1 | $19 |
| Boston Scientific | 1 | $16 |
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
$10,258 in reported general payments places this provider in the 90th percentile of 121 radiation oncology providers in Virginia.
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 |
|---|---|---|
| OrgovyxRelugolix | 16 | $42,745 |
| Tamsulosin Hcl | 26 | $367 |
| Ciprofloxacin Hcl | 14 | $13 |
Paid to pharmacies, not to this prescriber.
Other radiation oncology in Fairfax
- Daniel KimFairfax$406K
- Samir KananiFairfax$90K
- Gopal BajajFairfax$23K
- Ashish ChawlaFairfax$14K
- Kevin ChoeFairfax$8K
- Harold AgbahiweFairfax$7K
- Lonika MajithiaFairfax$5K
- Tobias ChapmanFairfax$2K
- Kathryn MarqueenFairfax$2K
- Michael EblanFairfax$1K
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.