Certain aspects relate to methods and apparatus for a flexible transmission unit and acknowledgement feedback timeline for low-latency communication. As described herein, a UE may receive, within a subframe a first portion of a downlink control region scheduling at least a first data unit, wherein the subframe comprises at least two TTIs and wherein the subframe comprises the downlink control region, a data region, and an uplink control region, receive the first data unit in a first TTI of the data region, receive a second data unit in a second TTI of the data region, and separately acknowledge receipt of the first and second data units. According to aspects, the acknowledgment for the first data unit may occur in the same subframe as the transmission of the first data unit. A BS may perform corresponding operations.