If you have your GovX.com account, then you can save 20% on Showtime through GovX.com. Showtime goes for $10.99 without any discounts but you can get it for $8.99/month if you are active duty military, veterans of the United States Armed Forces including National Guard and Reserves, their spouses and dependents, First Responders and Law Enforcement. You can cancel your subscription at any time.
If you do not have a GovX.com membership, you can sign up for free and save $15 off your first order using this link. Also you can earn $10 back after every $200.