From what I know, federal law provides extensive protection against attachment of pension benefits. This can be found both with Employment Retirement Income Security Act's (ERISA) "spendthrift rule" and the Internal Revenue Code (IRC 401(a)-13) provides similar as does federal bankruptcy law. State laws can also provide protections. Social Security payments are protected with the exception of orders concerning domestic relations and amounts owed to the federal government (such as outstanding student loans.)
