Hi, Nancy!
Once you hit your 180 booking window you are welcome to make your
Disney dining reservations. You do not need to have a "paid in full" reservation to make your dining plans.
If you have a Disney resort reservation, make sure to be logged into your My Disney Experience account when booking dining. This will allow you to
book at your 180 mark, with 10 days after that so you can book your dining for your entire trip (up to 10 days).
For hard to get restaurants, such as
'Ohana at Disney' s Polynesian Village Resort or Cinderella's Royal Table in the Magic Kingdom, you will want to book those as soon as you are at that 180 mark as the time slots for these super fun locations book up quickly.
Have fun booking all your dining reservations. If you book my favorite -
Chef Mickey's - make sure you say "HI" to Mickey and the Gang for me!
Cathy