Company: CSTL
Filing Date: 2025-11-03
Form Type: S-8
Source: 0001628280-25-048270
Chunk: 1

Company: CASTLE BIOSCIENCES INC
Filing Date: 2025-11-03
Form: S-8
Chunk 1
---
 Registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. o

### EXPLANATORY NOTE
This Registration Statement on Form S-8 (this "

#### Registration Statement
") is being filed by Castle Biosciences, Inc. (the “

#### Registrant
”) with the Securities and Exchange Commission (“

#### SEC
”) to register an additional 700,000 shares of common stock, par value $0.001 under the Castle Biosciences, Inc. 2022 Inducement Plan. In accordance with the instructional note to Part I of Form S-8 as promulgated by the SEC, the information specified by Part I of the Form S-8 has been omitted from this Registration Statement. Pursuant to General Instruction E to Form S-8, the contents of Registrant’s registration statement on Form S-8 (File No. 333-270146) , previously filed with the SEC on March 1, 2023, and Registrant's registration statement on Form S-8 (File No. 333-275881) , previously filed with the SEC on December 4, 2023, are incorporated herein by reference, except that the provisions contained in Part II of such earlier registration statement are modified as set forth in this Registration Statement.

This Registration Statement is being filed for the purpose of registering additional securities of the same class as other securities for which registration statements of the Registrant on Form S-8 relating to the same employee benefit plans are effective

# PART II

### INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

## ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.
The Registrant hereby incorporates by reference into this Registration Statement the following documents previously filed by the Registrant with the SEC:

(a) The Registrant’s Annual Report on Form 10-K for the year ended December 31, 2024, filed with the SEC on February 2 7 , 202 5 (and any portions of the Registrant’s Definitive Proxy Statement on Schedule 14A filed on

April 9, 2025 , that are incorporated by reference into its Annual Report on Form 10-K for the year ended December 31, 2024).

(b) The Registrant’s Quarterly Reports on Form 10-Q for the quarters ended March 31, 2025, June 30, 2025