dishwasher not draining at end of cleaning cycle

My Maytag dishwasher drains after the pots and pans cycle, the normal wash cycle, and the light wash cyle but it won’t drain completely at the end of the rinse cycle. There is about 1/2 inch of water left in the bottom of the tub. My drinking glasses all have spots and moisture on them. Can you give me some repair advice? Thanks