Do I need to have a living trust or is a will enough for a terminal relative?

I don't believe you require a trust. A trust would merely keep the disposition of assets out of court (probate). A will becomes effective at death, whereas a trust becomes effective the date it's signed. Your aunt may not be able to execute a trust at this stage of her life. What would you transfer into the trust? You've done the upfront work with the house (assuming it's titled as JTWROS), and ownership of investments will transfer at death.

To be certain, meeting with an elder care atty is always a good idea.

PS- my wife and I graduated from Muskego High and were married for 52 years before her passing.

Please confirm that the house is joint tenants with right of survivorship, not tenants in common. Your state may use different terms, but you want to make sure that half of the house isn't going to go into probate rather than transfer on death.

Please see an Elder Law Attorney to ask this question. Is there currently a will? If bank accounts are jointly held then it seems to me you are the surviving holder of the accounts. POD are easily passed to the survivor, as simple as showing up to the bank with ID. The home should also not be difficult and you are the only survivor, would be the only heir. However, when an elder passes, if they owe things things their assets stand to pay for what they owe. You should take the simple will, if that is what you have, to an elder law attorney. If the elder has dementia no new will or changes can be done. If there is no will at all or no trust, then I don't honestly have the slightest idea how that would work with medicaid recovery, with any bills and etc. In lieu of giving any faulty advice on an estate this big you should definitely get some advice. You are speaking of 12 million estate and only about 350 for an hour of an elder law attorney time. I don't think trust is needed as that would entail getting the home, now owned by you both, into the trust, complications not necessary with one heir. Get a trusted attorney for advice.