Methods and apparatus for expressing two or more extended information elements (IEs) of a MAP message using a single Extended or Extended-2 Downlink Interval Usage Code (DIUC) or Uplink Interval Usage Code (UIUC) in an orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) frame are provided. This enhancement, called extensible Extended IE mapping, allows the WiMAX network to include more IEs into the DL-MAP and UL-MAP messages as the IEEE 802.16 family of standards evolves. Without this enhancement, all of the new IEs may most likely have to be included in the data bursts, and a user terminal (e.g., a mobile station) cannot decode these data-burst IEs unless the user terminal receives the Downlink Channel Descriptor (DCD) message(s).