A method includes associating each block of a plurality of blocks of a memory device with a corresponding frequency access group of a plurality of frequency access groups based on corresponding access frequencies, and performing scan operations on blocks of each of the plurality of frequency access groups using a scan frequency that is different from scan frequencies of other frequency access groups. A scan operation performed on a frequency access group with a higher access frequency uses a higher scan frequency than a scan operation performed on a frequency access group with a lower access frequency.