Well, I've only been with DISH for 4 weeks so I know that my contract ends in November, 2020. I haven't been able to find a way with the DISH app or online to get a clear answer to the length of the contract but I'm certain that you should be able to get an answer from support via chat or phone. We came to DISH after the current face-off between DISH and ATT/Directv/HBO began because we realized that we were not watching HBO as much as the other premium channels. Yes, there were some series that we had watched but it was simply not worth it to us to remain customers of Directv after what ATT did to their service. Thus far, DISH has been a HUGE improvement. Recent articles in the business/media circles suggest that these disputes and blackouts will be the way of the future as mega mergers continue to create monopolies.
I was a DirecTV subscriber for 12 years and left for Dish about 9 months ago. DirecTV doesn't have anything even close to the Dish Hopper 3 with its 16 tuners. Granted I don't subscribe to any of the premium channels so I don't miss HBO or Cinemax or any of the other premium channels.
The Hopper 3 is not perfect, however it is light years ahead of any of the DirecTV receivers. After 9 months I am very glad that I made the switch.