March 22, 2016

March 22, 0000

Xxxxx Xxxxxx Bank and Trust Company Xxxxxx Xxxxxx Building

000 Xxxxxxx Xxxxxx

Xxxxx Xxxxxx, Xxxxxxxxxxxxx 0000 l Location Code: JQBS

Attention: Xxxxxxx X. Xxxxxxx

Re: ADMIN ISTRATION AGREEMENT - NEW PORTFOLIO

Ladies and Gentlemen:

Please be advised that AMERICAN CENTURY WORLD MUTUAL FUNDS, INC. has established a new series of shares to be known as AMERICAN CENTURY WORLD MUTUAL FUNDS, INC. FOCUSED INTERNATIONAL GROWTH FUND (the "New Portfolio").

In accordance with Section 1, the Appointment of Administrator provision, of the Administration Agreement dated as of July 29, 2011 (the "Administration Agreement") by and between American Century Investment Management, Inc. ("ACIM") and State Street Bank and Trust Company, the undersigned hereby requests that your bank act as Administrator for the New Portfolio under the terms of the Administration Agreement. In connection with such request, the undersigned hereby confirms to you, as of the date hereof, its representations and warranties set forth in the Administration Agreement. Capitalized terms used herein without definition shall have the meanings ascribed to them in the Administration Agreement.

Kindly indicate your acceptance of the foregoing by executing two copies of this letter agreement, returning one to ACIM and retaining one for your records.

Sincerely,

AMERICAN CENTURY INVESTMENT MANAGEMENT, INC. on

behalf of AMERICAN CENTURY WORLD MUTUAL FUNDS, INC. -

FOCUSED INTERNATIONAL GROWTH FUND

By: /s/ C. Xxxx Xxxx

Name: C. Xxxx Xxxx

Title: Vice President, Duly Authorized

Agreed and Accepted:

STATE STREET BANK AND TRUST COMPANY

By:    /s/ Xxxxxx Xxxxx    

Name: Xxxxxx Xxxxx

Title:    Executive Vice President, Duly Authorized

Effective Date:    March 28, 2016