For many families, receiving Supplemental Security Income (SSI) for a child with autism provides essential financial stability. The monthly payments often help cover therapy costs, transportation, educational support, and daily living expenses that insurance may not fully pay for. That is why many parents are shocked when they receive a letter from the Social Security Administration stating that their child’s benefits may stop after turning 18. In many cases, the young adult still has the same autism diagnosis, yet they suddenly no longer qualify under SSI rules. The confusion usually comes from a major policy shift called the age-18 redetermination process.