Summary Prospectus, Prospectus and Statement of Additional Information Supplement Supplement dated June 16, 2017

One Choice^® In Retirement Portfolio n One Choice^® 2020 Portfolio n One Choice^® 2025 Portfolio

One Choice^® 2030 Portfolio n One Choice^® 2035 Portfolio n One Choice^® 2040 Portfolio

One Choice^® 2045 Portfolio n One Choice^® 2050 Portfolio n One Choice^® 2055 Portfolio

One Choice^® 2060 Portfolio n One Choice^® In Retirement Portfolio R6 n One Choice^® 2020 Portfolio R6

One Choice^® 2025 Portfolio R6 n One Choice^® 2030 Portfolio R6 n One Choice^® 2035 Portfolio R6

One Choice^® 2040 Portfolio R6 n One Choice^® 2045 Portfolio R6 n One Choice^® 2050 Portfolio R6

One Choice^® 2055 Portfolio R6 n One Choice^® 2060 Portfolio R6 n One Choice^® Portfolio: Very Conservative One Choice^® Portfolio: Conservative n One Choice^® Portfolio: Moderate

One Choice^® Portfolio: Aggressive n One Choice^® Portfolio: Very Aggressive

(Summary Prospectuses, Prospectuses and Statement of Additional Information dated December 1, 2016)

Global Allocation Fund

(Summary Prospectus, Prospectus and Statement of Additional Information dated April 1, 2017)

Multi-Asset Income Fund n Strategic Allocation: Conservative Fund n Strategic Allocation: Moderate Fund n Strategic Allocation: Aggressive Fund

(Summary Prospectuses, Prospectuses and Statement of Additional Information dated April 10, 2017)

Effective June 30, 2017, Richard Weiss is promoted to Chief Investment Officer — Multi-Asset Strategies. In addition, Scott Wittman has announced his plans to leave American Century Investments. As a result, he will no longer manage the funds listed above as of June 30, 2017.

^©2017 American Century Proprietary Holdings, Inc. All rights reserved.

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