Apparatuses and methods for row hammer counter mat. A memory array may have a number of memory mats and a counter memory mat. The counter mat stores count values, each of which is associated with a row in one of the other memory mats. When a row is accessed, the count value is read out, changed, and written back to the counter mat. In some embodiments, the count value may be processed within access logic of the counter mat, and a row hammer flag may be provided to the bank logic. In some embodiments, the counter mat may have a folded architecture where each sense amplifier is coupled to multiple bit lines in the counter mat. The count value may be used to determine if the accessed row is an aggressor so that its victims can be refreshed as part of a targeted refresh.