Systems, methods, and instrumentalities are disclosed for adaptation of multiple input multiple output (MIMO) mode in mmW Wireless Local Area Network (WLAN) systems. A first station (STA) may receive a mode change request from a second STA. The mode change request may indicate a mode change for a MIMO mode, a polarization mode, and/or an orthogonal frequency-division multiple access (OFDMA) mode. The mode change request may include one or more STA fields. The one or more STA fields may include a STA field associated with the first STA. Each of the one or more STA fields may include a MIMO mode subfield, a polarization mode subfield, and/or an OFDMA mode subfield. The first STA may change the MIMO mode, the polarization mode, and/or the OFDMA mode, for example, based on the mode change request. The first STA may send a mode change response to the second STA.