Insurance answer needed - we're paying additional $4000 after Medicare and the policy has not paid any of the billing.

This is what I suggest. Call your office of aging and ask if there is someone who can help you get your insurances straight. I think your over insured. Why pay for something you are getting nothing in return.

Are you saying that Medicare is paying for everything and that your supplement has not been needed? How old is your husband?
The last year of my mom’s life her supplement policy was about $4,000 but she was 97 and there was no deductible. But she had the same supplement for over 30 yrs so maybe that made a difference.
She never had to pay anything except her premium. Medicare paid the 80% and her supplement paid the rest.
However, my mom lived at home. Medicare doesn’t pay for long term care. If you are expecting it to kick in on that, it won’t.
Im sure you know that the medigap plan only pays for the things that Medicare approves and pays 80% of. So, I guess you are saying that your husband has charges that aren’t covered by Medicare that he is paying? Those charges would have nothing to do with the supplement.
Thats how I understand how the supplement works. Do you understand it differently?
Perhaps you could give us a bit more information about what you are expecting from the supplement.

Medicare plus BC/BS should be enough. 4k a year is a lot for a supplimental and one that probably has a very high deductible. That is probably why no payments. Tell this to the people telling you to keep it. You can't afford it and the out of pocket you end up paying because of deductables.

This is not something that I have heard of.
You might want to talk to a Patient Advocate and get all the details as to what they need, what is paying for what. If there is no patient advocate ask to talk to a Social worker they may also figure out that is going on.
Another course of action would be talk to an Elder Care attorney and see if they can navigate the VA quagmire.