I am beneficiary of my late ex husband's 401k. I have already received the check. Am I allowed to keep it.

Your question seems to involve enough money that you really should retain an expert in person to consult. Most student loan debt gets retired by the death of the borrower - look into that. If you were the named beneficiary of the 401 and there is no claim of duress or malfeasance in naming you then the money should be yours.

Let's deal with the student loan first. If it was a subsidized loan, it is considered forgiven when he died. Navient is the name of the agency that now takes care of Sallie Mae loans to students. I would suggest that you locate the paperwork on the loan to determine whether or not it was federally subsidized or not. If your divorce decree simply stated that you retained your own retirement and did not address beneficiaries, then you are the owner of the proceeds of the retirement policy upon your ex' death. I would still suggest that you contact a lawyer locally to get some fact specific advice.

I agree with my colleagues about the student loan issue. As for the 401(k), it is governed by a federal law called the Employee Retirement Income Security Act (ERISA). This law trumps any contrary state laws. Under ERISA, beneficiary designations remain the same regardless of a divorce. The law requires the 401(k) participant to designate new beneficiaries after the divorce is finalized. Otherwise, the ex-spouse will receive it. This is true even if a Qualified Domestic Relations Order (QDRO) was entered into, dividing the retirement benefits of the parties, as a part of the divorce.