The present invention relates to a method for transmitting and receiving data in a wireless access system and a terminal therefor. The method comprises the steps of: receiving an instruction message which instructs transmission of uplink resource allocation information via a physical downlink shared channel (PDSCH) from a base station; determining whether the resource allocation information is a first downlink resource allocation information based on the instruction message, upon receiving resource allocation information set to a flag value that indicates uplink resource allocation information, from the base station via a physical downlink control channel (PDCCH); receiving uplink resource allocation information via the PDSCH according to the first downlink resource allocation information from the base station; and transmitting uplink data to the base station via a physical uplink shared channel (PUSCH) according to the uplink resource allocation information.