---
schema_version: "secwatch.filing_event.v1"
accession: "0001447362-23-000065"
form_type: "8-K"
ticker: "CSTL"
cik: "0001447362"
company_name: "CASTLE BIOSCIENCES INC"
filed_at: "2023-05-03T23:59:59+00:00"
generated_at: "2026-06-16T00:51:37.313165+00:00"
event_type: "earnings"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Castle Biosciences Q1 revenue up 57% to $42M; reaffirms FY 2023 guidance $170-180M

## Summary
- Delivered 14,916 total test reports (+73% YoY); DecisionDx-Melanoma 7,583 (+26%), DecisionDx-SCC 2,411 (+111%).
- Revenue $42.0M (+57% YoY); adjusted revenue $43.4M (+65%); net loss ($29.2M) vs ($24.6M) prior year.
- Gross margin 70.5% (adjusted 76.5%); cash & marketable securities $232.1M as of March 31, 2023.
- Reaffirms full-year 2023 revenue guidance of $170-180M; Q1 cash use includes $17.7M non-recurring bonus/benefit payments.

## SEC filing metadata
- accession: 0001447362-23-000065
- form_type: 8-K
- ticker: CSTL
- cik: 0001447362
- company_name: CASTLE BIOSCIENCES INC
- filed_at: 2023-05-03T23:59:59+00:00
- event_type: earnings
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 2.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1447362/000144736223000065/0001447362-23-000065-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1447362/000144736223000065/cstl-20230503.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001447362-23-000065
- JSON: https://secwatch.observer/filing/0001447362-23-000065.json
- Plain text: https://secwatch.observer/filing/0001447362-23-000065.txt

## Key facts
- Earnings Releases
  CASTLE BIOSCIENCES INC reported the first quarter ended March 31, 2023 results: revenue $42.0 million, net income $(29.2) million. Guidance reaffirmed.
  - Period: the first quarter ended March 31, 2023
  - Revenue: $42.0 million
  - Net income: $(29.2) million
  - Guidance: reaffirmed
  - Result: reported results
  source text: Castle Biosciences Reports First Quarter 2023 Results Q1 2023 revenue increased 57% over Q1 2022 to $42 million Q1 2023 total test reports increased 73% over Q1 2022 Reaffirming full-year 2023 revenue is expected to be between $170-180 million
  evidence_url: https://www.sec.gov/Archives/edgar/data/1447362/000144736223000065/0001447362-23-000065-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.