You have a BIG problem on your hands, and your Dad is totally unrealistic. Each child (and any his spouse, if living) are ENTITLED BY LAW to a share of his estate — unless me makes a valid will or revocable llving trust to document his wishes! PERIOD!
The minute his death certificate is recorded by the doctor/hospital/medical examiner, the state will have the right — in the absence of one of those documents — to take over the estate and appoint a probate attorney who will freeze the assets that were in your dad’s name –and let the probate court decide who gets what, according to the laws of the state of death. And this will likely take at least a year in the absence of a will!
And, for sure, your sibling will be entitled to his/her share!
Please show this answer to your father right now!! He can find an estate planning attorney in the area where he lives at www.search-attorneys.com.
And please tell him from me that he shouldn’t procrastinate. I’m superstitious, and I truly believe that if you don’t have an estate plan, you’re tempting fate. I’m glad he is in good health, but accidents do happen!