A trust designed to hold and disburse property for the benefit of an SSI recipient so that SSI and Medicaid won't consider the trust property or disbursements to be a resource or income. To accomplish this purpose, the trust typically gives the trustee sole discretion over trust disbursements and bars the trustee from making disbursements that would impair the beneficiarys eligibility for SSI and Medicaid. In addition, the trust must be for the beneficiarys sole benefit and bar creditors from going after trust assets. A special needs trust funded with the beneficiarys own property (a self-settled trust) is subject to additional restrictions. Also called a supplemental needs trust.