A memory apparatus and method of operation are provided. The apparatus includes memory cells connected to one of a plurality of word lines including at least one edge word line and a plurality of other data word lines. The memory cells are arranged in strings and configured to retain a threshold voltage corresponding to one of a plurality of data states. The memory apparatus also includes a control means coupled to the plurality of word lines and the strings. The control means is configured to identify the at least one edge word line. The control means is also configured to periodically apply a program voltage to the at least one edge word line to reprogram the memory cells associated with the at least one edge word line without erasing the memory cells associated with the at least one edge word line.