As Filed with the U.S. Securities and Exchange Commission on January 18, 2019

1933 Act File No. 333-221045

1940 Act File No. 811-23305

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549
__________________
FORM N-1A
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REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933	☒
Pre-Effective Amendment No.	☐
Post-Effective Amendment No. 16	☒
and/or
REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940	☒
Amendment No. 18	☒
(Check appropriate box or boxes.)
__________________
American Century ETF Trust
__________________
4500 MAIN STREET, KANSAS CITY, MISSOURI 64111   (Address of Principal Executive Offices)                  (Zip Code)
REGISTRANT’S TELEPHONE NUMBER, INCLUDING AREA CODE: (816) 531-5575
CHARLES A. ETHERINGTON 4500 MAIN STREET, KANSAS CITY, MISSOURI 64111 (Name and Address of Agent for Service)
Approximate Date of Proposed Public Offering: As soon as practicable after the effective date of the Registration Statement
It is proposed that this filing will become effective (check appropriate box)

☐	immediately upon filing pursuant to paragraph (b)
☒	on February 16, 2019 at 8:30 a.m. Central 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)
☐	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

Pursuant to Rule 485(b)(1)(iii) under the Securities Act of 1933, this Post-Effective Amendment No. 16 is being filed for the sole purpose of designating a new effective date, February 16, 2019, for the Registrant’s Post-Effective Amendment No. 3 previously filed on June 18, 2018 pursuant to Rule 485(a) (the “Amendment”).

The effectiveness of the Amendment was previously delayed pursuant to Rule 485(b)(1)(iii) as follows: Post-Effective Amendment No. 7 filed on August 31, 2018, Post-Effective Amendment No. 10 filed on September 28, 2018, Post-Effective Amendment No. 11 filed on October 26, 2018, Post-Effective Amendment No. 12 filed on November 23, 2018, and Post-Effective Amendment No. 13 filed on December 21, 2018.

This Post-Effective Amendment No. 16 incorporates by reference the information contained in Parts A, B and C of the Amendment.

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements for effectiveness of this Registration Statement amendment pursuant to Rule 485(b) promulgated under the Securities Act of 1933, as amended, and has duly caused this Registration Statement to be signed on its behalf by the undersigned, duly authorized, in the City of Kansas City, State of Missouri on the 18th day of January, 2019.

	American Century ETF Trust
By:	* _________________________________
	Jonathan S. Thomas
	President

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

SIGNATURES	TITLE	DATE
* _____________________________	Chairman, Trustee and President	January 18, 2019
Jonathan S. Thomas
* _____________________________	Chief Financial Officer and Treasurer	January 18, 2019
R. Wes Campbell
* _____________________________	Trustee	January 18, 2019
Reginald M. Browne
* _____________________________	Trustee	January 18, 2019
Ronald J. Gilson
* _____________________________	Trustee	January 18, 2019
Barry A. Mendelson
* _____________________________	Trustee	January 18, 2019
Stephen E. Yates

*By:	/s/ Kathleen Gunja Nelson
	Kathleen Gunja Nelson
	Attorney in Fact

Pursuant to Power of Attorney, dated September 12, 2018 (filed electronically as Exhibit q1 to Post-Effective Amendment No. 14 to the Registration Statement of American Century ETF Trust on December 28, 2018, File No. 333-221045, and incorporated herein by reference).

Secretary’s Certificate, dated September 12, 2018 (filed electronically as Exhibit q2 to Post-Effective Amendment No. 14 to the Registration Statement of American Century ETF Trust on December 28, 2018, File No. 333-221045, and incorporated herein by reference).