Acker agreed to a contract Wednesday with the Colts, Adam Caplan of SiriusXM Radio reports.
Acker appeared in all 16 games for the Chiefs in 2017 and finished with 23 tackles and one interception while playing over 200 snaps on both defense and special teams. He's off the IDP radar at present, but that could change if he somehow manages to carve out a significant role within the Colts' unsettled cornerback group.