Apparatuses, systems, methods, and computer program products are disclosed for memory array addressing. An addressing circuit is configured to receive an address for an operation on an array of multiple memory regions. An address includes a row address and a column address both multiplexed into the address and received with an activate command for an operation. A row buffer for an array of multiple memory regions is configured to store data identified by multiplexed row and column addresses from the multiple memory regions. Data of an operation is selected from a row buffer based on a second address received with a subsequent command for the operation.