Shirin Attarian, MD
Hematology & Oncology · Orange, CANPI 1427310713
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $2,538 of the $3,079 with a category attached, or 82.4%. Sanofi accounts for 82.4% of it on its own, with 4 other manufacturers making up the rest. Reporting peaked in 2021 at $2,538 and has fallen 94.3% since, to $145 in 2025. That places this record below the midpoint for hematology & oncology clinicians in CA, where the typical reported total is $3,371.
Across 6 payments — averaging $513.11 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Sanofi$3K
- Regeneron Healthcare Solutions, Inc.$244
- Johnson & Johnson$145
- Sandoz$125
- Merck$26
Across 7 payments — averaging $11,477 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.
- Merck$48K
- Coherus Oncology, Inc.$33K
What the payments were for
- Consulting fees$2,53882%
- Grants$1254%
- Food & beverage$38913%
- Education$261%
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 |
|---|---|---|
| Sanofi | 1 | $2,538 |
| Regeneron Healthcare Solutions, Inc. | 2 | $244 |
| Johnson & Johnson | 1 | $145 |
| Sandoz | 1 | $125 |
| Merck | 1 | $26 |
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.
- LIBTAYO$2,782
How this compares
$3,079 in reported general payments places this provider in the 45th percentile of 1,363 hematology & oncology providers in California.
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 |
|---|---|---|
| Dexamethasone | 27 | $353 |
| Prochlorperazine Maleate | 26 | $302 |
| Ondansetron Hcl | 20 | $299 |
| Olanzapine | 36 | $182 |
Paid to pharmacies, not to this prescriber.
Other hematology & oncology in Orange
- Catherine CoombsOrange$786K
- Arash Rezazadeh KalebastyOrange$516K
- Misako NagasakaOrange$507K
- Elizabeth BremOrange$335K
- May ChoOrange$334K
- Angela FleischmanOrange$255K
- Dennis SlamonLos Angeles$3.1M
- Sandra HorningStanford$2.5M
- Mohammadbagher ZiariCorona$2.5M
- George YaghmourLos Angeles$1.9M
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.