Moving in and buying a house together with my parents. How is this done?

Gift tax is paid by the giver not the recipient. In addition gift tax is generally paid at the final tax return at death - and even then it is calculated based on the total given away over a life time. The last time I looked into it, the figure was over one million. The vast amount of people worry needlessly over gift tax.

It would probably be ideal to get a tax professional, estate planner, or even an eldercare attorney to weigh in on the plan - there may be some little thing to do a certain way that makes it legit, or there may be a pitfall in there somewhere.

If you don't ever have to apply for Medicaid for your parents, the situation is fairly straightforward. They could leave their third of the house to you after both your parents pass. The only difficulty would be if the have to go on Medicaid or incur a large debt. A lien could be put on their portion of the house. You would have to take care of that if it came up so you wouldn't lose the house.

If you don't see Medicaid in the future and you get along with the parents, this seems like a very good arrangement that will let you buy a better house. I do hope you get along well.