A well-meant inheritance can cost a person with a disability the benefits that pay for their housing, medical care, and daily support. This article explains why that happens, and how special needs planning prevents it. It covers the difference between benefits that are means-tested and benefits that are not, the resource and income rules that actually trigger disqualification, and the three kinds of trusts that hold assets without counting them. It explains the crucial distinction between a first-party trust funded with the beneficiary's own money — which carries a Medicaid payback obligation — and a third-party trust funded by family, which does not. Separate parts address ABLE accounts, pooled trusts, the in-kind support rules that reduce benefits when a trustee pays the wrong bills, and the mistakes families make in wills and beneficiary designations. Examples run throughout, including the settlement that must be structured before it is received. The article is written for families, trustees, and lawyers new to the field.