The present invention provides methods and apparatus for performing initial access based on the Application specific Congestion control for Data Communication (ACDC) category mapping scheme. One of methods for performing initial access based on an Application specific Congestion control for Data Communication (ACDC) category in a wireless access system, the method performed by a user equipment (UE) and comprising: receiving, from a home network, ACDC configuration information representing ACDC categories supported by the home network; receiving, from a serving network, ACDC category access parameters including barring information of the serving network; and performing the initial access based on the ACDC configuration information and the ACDC category access parameters when an application packet to be transmitted is generated, wherein the barring information includes barring time value and barring factor value representing a probability of denied or deferred of the initial access according to ACDC category of the serving network.