Post-Effective Amendment to Post-Effective Amendment by Investment Company (Form 485BXT)

As filed with the Securities and Exchange Commission

on March 26, 2026

Securities Act File No. 33-58125

Investment Company Act File No. 811-07261

U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	☒
Pre-Effective Amendment No.	☐
Post-Effective Amendment No. 66	☒
and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940	☒
Amendment No. 67	☒
(Check appropriate box or boxes)

Credit Suisse Trust

(Exact Name of Registrant Specified in Charter)

1285 Avenue of the Americas, New York, New York	10019
(Address of Principal Executive Offices)	(Zip Code)

Registrant's Telephone Number, Including Area Code: (212) 325-2000

Karen Regan

Credit Suisse Trust

1285 Avenue of the Americas

New York, New York 10019

(Name and Address of Agent for Service)

Copies to:

Justin L. Browder Simpson Thacher & Bartlett LLP 900 G Street, N.W. Washington, DC 20001

Bissie K. Bonner Simpson Thacher & Bartlett LLP 425 Lexington Avenue New York, New York 10017

Approximate date of proposed public offering:

It is proposed that this filing will become effective (check appropriate box)

☐

Immediately upon filing pursuant to paragraph (b)

☒

on April 1, 2026 pursuant to paragraph (b)

☐

60 days after filing pursuant to paragraph (a)(1)

☐

on (date) pursuant to paragraph (a)(1)

☐

75 days after filing pursuant to paragraph (a)(2), or

☐

on (date) pursuant to paragraph (a)(2) of Rule 485

If appropriate, check the following box:

☒

This post-effective amendment designates a new effective date for a previously filed post-effective amendment

EXPLANATORY NOTE

This Post-Effective Amendment No. 66 under the Securities Act of 1933, as amended (the "Securities Act") (Amendment No. 67 under the Investment Company Act of 1940, as amended (the "1940 Act")) to the registration statement on Form N-1A (the "Registration Statement") of Credit Suisse Trust (the "Registrant") is being filed pursuant to paragraph (b)(1)(iii) of Rule 485 under the Securities Act solely for the purpose of delaying, until April 1, 2026, the effectiveness of the registration statement for Commodity Return Strategy Portfolio, filed in Post-Effective Amendment No. 63 on December 3, 2025, pursuant to paragraph (a) of Rule 485 under the Securities Act.

This Post-Effective Amendment No. 66 incorporates by reference the information contained in Parts A, B and C of Post-Effective Amendment No. 63 to the Registrant's Registration Statement.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, the Registrant certifies that it meets all the requirements of effectiveness of this Registration Statement under Rule 485(b) of the Securities Act and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of New York, New York, on the 26th day of March, 2026.

CREDIT SUISSE TRUST
By	/s/ Omar Tariq
	Omar Tariq Chief Executive Officer and President

Pursuant to the requirements of the Securities Act of 1933, the Registration Statement has been signed below by the following persons in the capacities and on the dates indicated.

SIGNATURE		TITLE		DATE
/s/ Omar Tariq		Chief Executive Officer and President		March 26, 2026
Omar Tariq
/s/ Rose Ann Bubloski		Chief Financial Officer, Principal Accounting		March 26, 2026
Rose Ann Bubloski		Officer and Treasurer
/s/ William Ferri*		Chair of the Board		March 26, 2026
William Ferri
/s/ Douglas Barnard*		Trustee		March 26, 2026
Douglas Barnard
/s/ Ramona Heine*		Trustee		March 26, 2026
Ramona Heine
/s/ Louis Zurita*		Trustee		March 26, 2026
Louis Zurita

*By:	/s/ Tanya L. Boyle
	Tanya L. Boyle, as Attorney-in-Fact