MQDs are a metric used to help you achieve elite status with the Delta SkyMiles program, and they are based on how much you spend with Delta and partner airlines each year. You can use MQDs along with Medallion Qualifying Miles (MQMs) or Medallion Qualifying Segments (MQSs) to qualify for different levels of status with Delta. For example, you need $3,000 in MQDs, plus either 25,000 MQMs or 30 MQSs, to qualify for Silver status with Delta.