A qualified income trust, which is also referred to as a Miller trust, is a tool that allows someone to reduce his or her income and become eligible for Medicaid coverage. A qualified income trust is an irrevocable trust, which means once it's created he or she cannot revoke or change the trust without court action, except for under limited circumstances. It can be an effective estate planning tool, but it isn’t right for everyone, which is why you should speak to an attorney.