Methods and systems are disclosed for imminent read failure detection based upon unacceptable wear for non-volatile memory (NVM) cells. In certain embodiments, a first failure time is recorded when a first diagnostic mode detects an uncorrectable error within the NVM cell array using a first set of read voltage levels below and above a normal read voltage level. A second failure time is recorded when a second diagnostic mode detects an uncorrectable error within the NVM cell array using a second set of read voltage levels below and above a normal read voltage level. The first and second failure times are then compared against a threshold wear time value to determine whether or not an imminent read failure is indicated. The diagnostic modes can be run separately for erased NVM cell distributions and programmed NVM cell distributions to provide separate wear rate determinations.