Advance care planning is important to ensure that patients, when competent, can influence the kind of medical care they receive if they lose decision-making capacity. Because decisions by surrogates to for-go nutrition support remain controversial, specific inclusion of artificial nutrition and hydration as a part of advance care planning has taken on growing importance. This article reviews the choices about artificial nutrition and hydration that are possible using conventional advance directives such as the living will, the instructional directive, values histories, and combination directives. It summarizes the legal basis for such documents. It also describes the ways that physicians' orders to limit treatment can help implement decisions about the use of artificial nutrition and hydration. Finally, it stresses the importance of clarifying with patients and families the risks and benefits of nutrition support in a variety of common situations such as advanced dementia and metastatic cancer as an essential prerequisite to meaningful advance care planning.