Hi Beth!
Thank you for sending in your question to the Walt Disney World Moms Panel!
You can get the latest information on military discounts from Disney on the official
Military Discounts page. As you can see, there is a great 4 Day Promotion Military Ticket being offered but that promotion ends at the end of September. Last year the promotion was extended, but we don't know if that will happen again this year. You should check back closer to your trip. If that promotion gets extended then the service member could buy six tickets at that price. The tickets can be upgraded with the Park Hopper option and the Water Parks Fun & More option.
There is also currently a discount on stays at a Disney owned and operated hotel. Again, you should check back to see if that gets extended. However, there is also an Armed Forces Recreational Center right in the heart of Walt Disney World: The Shades of Green. The Shades of Green is a great place to stay and lodging cost is generally based on rank. You can also purchase special discounted military tickets there year round, though they are not as good at the 4 Day Promotional Military Ticket. The service member just needs his ID card.
Finally, discounted tickets can also be picked up at most military bases around the United States at the Morale, Welfare, and Recreation office. You would have to compare the price of tickets purchased there to the price of tickets purchased right at the Shades of Green.
I hope this helps! Good luck and please write back with more questions!