I am a licensed insurance agent in TN and KY, I've passed the Americas Health Care Programs (AHIP) test the past two years. Everyone selling Medicare or Medicaid products must pass this test annually. I've attended Humana's Veteran Insurance Seminar. As far as I know this is good info.
So, my wife and I went to Fort Campbell last week to get her a new ID card. I got a new card while I was there since mine was delaminated. They guys there took "indefinitelyf" off mine an added an expiration date the month before I turn 65. When I asked why they told me "when you sign up for Part B come back and we will issue you an indefinitely card." Part B is 144.60 a month this year. We shouldn't have to worry about Part A since we all worked at least 7.5 years. Our Veterans Affairs eligibility covers the drug plan or "Part D."
As of April 2019 Blanchfield Hospital isn't taking any more new 65 year old patients. You can still get your prescriptions there. Once you get your indefinitely card after applying for Part B at the local Social Security Office then you can apply for Tri-Care for Life. The guy there says it's a mess with people not applying for Part B when eligible then finding out they have a fine for the rest of their lives.
From what I can gather we are getting equal to a Medicare "G Plan" with Tri-Care for Life. No more 600.00 a year Tri-Care Prime after you turn 65. You'll either use docs that take Medicare, your local Veterans Affairs, or employer based plans that are accepted by Centers for Medicare and Medicaid Services (CMS.)
I can't tell you how many medically retired vets I've met that are not paying Part B or D. They run into big problems when the local installation or VA won't see them. The penalties are for the rest of your life. Go see Social Security when you're eligible for Medicare. A "G Plan' runs another couple hundred dollars a month depending on where you live and your age. We still get that benefit for our service.