Aspects of a method and system for parsing bits in an interleaver for adaptive modulations in a multiple input multiple output (MIMO) wireless local area network (WLAN) system are provided. The interleaver may assign at least one binary bit of information, among a plurality of binary bits of information to be transmitted, to one of a plurality of spatial streams based on a current modulation type. A subsequent binary bit of information, among a plurality of binary bits of information to be transmitted, may be assigned to a subsequent one of the plurality of spatial streams based on the current modulation type and/or a subsequent modulation type. The interleaver may assign at least one additional bit of information, among the plurality of binary bits of information to be transmitted, to one of a plurality of spatial streams based on the current modulation type and/or the subsequent modulation type.