If my dad is receiving social security benefits and Medicaid/Medicare but lives alone, if I decide to move in with him will it affect him?

Just looked at my nephews NJ Medicaid health renewal. All they asked, other than his info, was info on a spouse. So, I don't think you living with him will effect what he receives. Look at his last renewal, hope he keeps copies, and see what questions are asked.

Medicare and Social Security, like said, is not effected.

medicaid is based on his income alone not yours so his Medicaid eligibility won’t be affected. Medicare has nothing to do with income so it won’t be affected. His social security, regardless of what type he is on, will not be affected either since you are not his spouse.

Any financial arrangements between the two of you will be examined carefully.