Your husband passed away and his deceased parents were still the beneficiaries of his annuity. Who inherits the annuity?

You should consult with an attorney who specializes in probate law in your area ASAP. The proceeds may have transferred to his parents' estates. In that case, the proceeds would pass under their wills or under the state laws of intestacy to their heirs at law. The attorney must review the policy, whether it was owned by your husband's estate and your state laws. You may need to take the matter to court.