It is my understanding that being the spouse of a 100% diabled veteran entitles me to Champava which I have. When I turn 65 I will have to have Medicare my primary insurance and pay for Medicare B with Champava being the secondary insurance. Does anyone know how much this will cost a month?

Your spouse must be Total and Permanent. You should have received the information from Champva if you are eligible. Medicare changes price almost every year, so I can not tell you what it will be when you turn 65. Champva does not require Medicare, but I recommend it.