Amtrak is planning to acquire 28 trains with the aim of increasing seating capacity on the NEC by 40% compared with the existing Acela Express fleet, which will be replaced by the new trains.

A request for proposals closed on October 1 but Amtrak has not released details of the prospective bidders.

On December 3 the Federal Railroad Administration (FRA) announced that it would grant a waiver to both Amtrak and California High-Speed Rail Authority (CHSRA) excluding the pre-series trains for both orders from "Buy America" provisions requiring domestic final assembly of new rolling stock. The waiver will only apply to the first two trains for both contracts.