Methods and apparatus for providing transport block boundary flexibility are disclosed. In some aspects, a transmitter determines a plurality of blocks within a single transmission time interval (TTI), and transmits the plurality of blocks within the single TTI. Each of the plurality of blocks spans over a pre-defined period of time that is shorter than the single TTI. Each of the plurality of blocks includes data having a same logic channel identifier and a same header. A leading boundary and a trailing boundary of each of the plurality of blocks are aligned with one of: a leading boundary and a trailing boundary of a symbol; or a leading boundary and a trailing boundary of a code block. In additional aspects, a receiver receives these plurality of blocks within a single transmission time interval (TTI), and decodes a plurality of protocol data units in the plurality of blocks.