William Mack, MD
Neurological Surgery · Los Angeles, CANPI 1811163793
Payments from drug & device makers
What this record shows
This record is dominated by consulting fees: $4,200 of the $6,374 with a category attached, or 65.9%. Imperative Care, Inc accounts for 70.6% of it on its own, with 10 other manufacturers making up the rest. Reporting peaked in 2023 at $4,415 and has fallen 93.2% since, to $302 in 2025.
Across 26 payments — averaging $245.17 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Imperative Care, Inc$5K
- Microvention, Inc.$561
- Medtronic$411
- Penumbra, Inc.$274
- Viz.ai, Inc.$198
- Elekta, Inc.$162
- plus $266 from 5 others
Across 14 payments — averaging $7454.00 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.
- Medtronic$104K
What the payments were for
- Consulting fees$4,20066%
- Travel & lodging$2414%
- Food & beverage$1,93330%
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 |
|---|---|---|
| Imperative Care, Inc | 7 | $4,503 |
| Microvention, Inc. | 5 | $561 |
| Medtronic(2 entities) | 5 | $411 |
| Penumbra, Inc. | 2 | $274 |
| Viz.ai, Inc. | 1 | $198 |
| Elekta, Inc. | 1 | $162 |
| Balt USA, LLC | 1 | $113 |
| Medical Device Business Services, Inc. | 1 | $71 |
| Stryker | 1 | $32 |
| Phenox Inc. | 1 | $28 |
| Johnson & Johnson | 1 | $21 |
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
$6,374 in reported general payments places this provider in the 55th percentile of 773 neurological surgery 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 |
|---|---|---|
| BrilintaTicagrelor | 15 | $5,817 |
Paid to pharmacies, not to this prescriber.
Other neurological surgery in Los Angeles
- Larry KhooLos Angeles$2.8M
- Aaron Cohen-GadolLos Angeles$1.3M
- Geoffrey ColbyLos Angeles$1.1M
- Langston HollyLos Angeles$846K
- Linda LiauLos Angeles$783K
- Adam MamelakLos Angeles$678K
- Martin PhamLos Angeles$596K
- Carl LauryssenLos Angeles$571K
- Vivek MehtaLos Angeles$442K
- Patrick HsiehLos Angeles$345K
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.