My in laws signed their home over to their sons 12 years ago with the stipulation they could live there till they die.Now they are in a rest home;

It is likely that your in-laws have received benefits from a Medicaid program because they lack sufficient liquid assets and income to pay for their care. Under these circumstances, the life estate in their property, which they retained, is subject to a Medicaid lien, which means that Medicaid has the right to be repaid from the sale of the property for what it has laid out for their care. It is unclear whether the sons have received their remainder interest free and clear of the Medicaid lien under the circumstances you posit.