A method includes determining a first memory access count threshold for a first word line of a block of memory cells and determining a second memory access count threshold for a second word line of the block of memory cells. The second memory access count threshold can be greater than the first memory access count threshold. The method can further include incrementing a memory block access count corresponding to the block of memory cells that includes the first word line and the second word line in response to receiving a memory access command and refreshing the first word line when the memory block access count corresponding to the block of memory cells is equal to the first memory access count threshold.