Legal Question in Wills and Trusts in Illinois

Maybe, depending on the specifics of his decline and if your mother also owns the house. But my best advice is to buy the house from your parents in writing at a fair price with creative financing from them also in writing while they're both alive and not in further decline. A lawyer can help you structure the purchase. And it's a win-win, as both your parents need or at least want to sell the old house. Asking your father to make a bequest to you presumably against your mother's (his wife's) wishes is just asking for trouble and setting your family up for a fight that will accomplish little but help some lawyers fund their own kids' education, or their own retirements.

I agree with Attorney Stein regarding entering into specific purchase terms. As far as leaving his half in the will, that may not be that simple.

There are different forms of ownership. If they own as tenants by the entirety, then both their signatures would be needed to first break up the ownership and avoid the property going to the survivor. Arguably, the property can no longer be in tenancy by the entirety since it is not their principal residence, but the deed may still show it held that way if it was at one time. If the property is held as joint tenants, then your father would first have to sever the joint tenancy before leaving his interest to you in a will. If they hold as tenants in common, then he should be able to address his half through his will.

An attorney would also be able to look at a transfer on death instrument (TODI).

Any of this still leaves issues that you will face even if you co-own the property with your mother. Hence, the suggestion to work out purchase terms as a better option.

I suggest your father consult with an attorney and that your involvement be limited to avoid any arguments that you were unduly influencing him. Alternatively, you can meet with an attorney and send your parents an offer.