Federal law, passed in Washington, is at the core of the Medicaid system. State law, passed in Austin, is at the core of marital property agreements. Federal law typically dominates over any conflicting state law in order to create a more uniform legal system throughout the country. Texas law works in your favor. The Texas marital property system dictates that funds earned and assets acquired during marriage are community property, owned 50-50 by the spouses.
Any assets acquired before the marriage are separate property.
The system can be, and often is, changed with consent of the spouses in a marital property agreement like your prenuptial agreement. Your agreement can legally prevent the creation of community property. It is legal and enforceable in Texas. If you get a divorce, the courts will uphold its terms. But if you remain married and your husband goes to a nursing home, federal law works against you.