Certain aspects of the present disclosure provide techniques for carrier group based multiple-input multiple-output (MIMO) layers and antenna adaptation. A method that may be performed by a user equipment (UE) includes receiving a configuration of one or more groups of component carriers (CCs) and, for each group of CCs, one or more sets of configured maximum number of MIMO layers. Each set includes a configured maximum number of MIMO layers associated with each CC in the group. The UE receives an indication of at least one of the one or more sets and determines the configured maximum number of MIMO layers associated with each CC in the corresponding group of CCs based on the indication.