Filed under Rule 497(e)

Registration No. 33-52742

SunAmerica Series Trust

SA JPMorgan Large Cap Core Portfolio

(the “Portfolio”)

Supplement dated September 22, 2026

to the Portfolio’s Statement of Additional Information (“SAI”)

dated May 1, 2026, as supplemented and amended to date

Effective September 1, 2026, in the table under the section entitled “PORTFOLIO MANAGERS – Other Accounts,” in the subsection pertaining to J.P. Morgan Investment Management Inc. (JPMorgan), the information pertaining to Shilpee Raina is deleted and replaced with the following information for David Maccarrone:

 

Adviser/

Subadviser

 

Portfolio

Managers

  Other Accounts
(As of August 31, 2026)
  Registered Investment Companies   Pooled Investment Vehicles   Other Accounts
  No. of Accounts   Assets (in millions)   No. of Accounts  

Total Assets

(in millions)

  No. of Accounts  

Total Assets

(in millions)

JPMorgan  

David

Maccarrone

  0   $0   0   $0   0   $0

Capitalized terms used but not defined herein shall have the meanings assigned to them by the SAI.

PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.

SASTSAI-SUP7 (9/26)