Abstract: Apparatus and method for determining when to save values of read counters are disclosed. Read counters store values that indicate the number of reads in respective blocks of a memory device. The values of the read counters may be stored in volatile memory, and may be periodically stored to non-volatile memory. The frequency at which the values of the read counters are stored to non-volatile memory may be dependent on the read disturb effect. One measure of the read disturb effect may be based on the characteristics of the respective blocks of the memory device, such as whether the respective block is open/closed, has on-chip copy, and whether the read is to a boundary wordline.