You are trying to do some estate planning which is really great but this type of elder care planning requires you sit down with a qualified planner/attorney to help. Generally, if he enters under Medicaid then his interest in the house won't count against him should he need to enter a nursing home, because a person's primary residence is exempt when Medicaid counts a person's assets in determining eligibility. Upon his death though Medicaid may be able to make a claim against his 50% interest in the house. So consider speaking with an attorney about how to avid that sooner rather than later.  Good luck.