MEDIUMOutside partyCustomer
44%
Medicare
“10-K Item 1: 'Our revenue from patients covered by Medicare as a percentage of total revenue, was 44% for the year ended December 31, 2025.'”
CSTL · Concentration risk · 10-K extracted
Castle Biosciences (CSTL) concentration risks
Updated
The most significant concentration Castle Biosciences discloses is Medicare at 44%, classified MEDIUM by disclosed size. Below: the full set from the latest 10-K — verbatim quotes, filing references, and a synthesis of what these exposures mean together.
Model-generated analysis — not investment advice. Not a registered investment advisor. Past performance does not guarantee future results.
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Source: Castle Biosciences’s SEC Form 10-K filed — view the filing on SEC EDGAR ↗
At a glance
Disclosed-size breakdown · 2 disclosed concentrations
HIGH0
MEDIUM1
LOW1
Disclosed concentrations
Each card carries a disclosed-size chip (HIGH / MEDIUM / LOW — how large the exposure is as a share of revenue, not how dangerous it is) and a nature tag: Built-in(the company’s own model, geography, or products) or Outside party (an external customer, supplier, or distributor it relies on).
LOWOutside partyCustomer
16%
single commercial payor
“10-K Item 1: 'there was a commercial payor from which 16% of our revenue from patients was derived for the year ended December 31, 2025.'”
TrendMatrix Research · concentration synthesis
What these concentrations mean together
updated 2026-07-06Castle Biosciences' concentration risk runs through its payor mix rather than any product or supplier exposure. Revenue from patients covered by Medicare represented 44% of total revenue for the year ended December 31, 2025 — a moderate-share dependency on a single payor type — while a single commercial payor contributed a further 16% of revenue from patients, a comparatively modest exposure. Both are dependency-type risks tied to reimbursement decisions rather than structural features of the underlying diagnostics business. Because Medicare's share is meaningfully larger than the single commercial payor's, a change in Medicare coverage or reimbursement policy for the company's tests would be the more consequential of the two exposures and the one most likely to move the verdict; the commercial payor concentration, while worth monitoring, represents a smaller slice of the revenue base. Together, these two payor-level dependencies mean Castle Biosciences' revenue is more sensitive to reimbursement policy decisions from a small number of payors than to broader end-market or supply-chain dynamics.
For the engine’s reasoning on CSTL’s current verdict — including which dimensions drove the score — see the per-dimension breakdown.
Industry peers · Diagnostics & Research
Peer concentration profile
| Symbol | Name | HIGH | MEDIUM | LOW | Total |
|---|---|---|---|---|---|
| ADPT | Adaptive Biotechnologies Corpor | 2 | 0 | 0 | 2 |
| CDNA | CareDx, Inc. | 1 | 1 | 0 | 2 |
| CRL | Charles River Laboratories Inte | 1 | 1 | 0 | 2 |
| BLLN | BillionToOne, Inc. | 1 | 0 | 0 | 1 |
| CSTL● | Castle Biosciences, Inc. | 0 | 1 | 1 | 2 |
| A | Agilent Technologies, Inc. | 0 | 1 | 0 | 1 |
Concentration counts reflect items disclosed in each peer’s most recent 10-K; disclosed-size classification uses TrendMatrix’s internal 10-K extraction taxonomy.