In this article we describe how an advance care planning (ACP) program was developed, implemented, and evaluated. Our aim was to improve ACP in palliative care for people with intellectual disability (ID). The program was based on 10 competencies needed for ACP and was developed in a co-design process with people with ID, relatives, and professionals. The program was implemented in six ID care organizations in the Netherlands and consisted of an information pack, a training course, and an implementation interview about implementing ACP. Professionals indicated that their competencies had improved, particularly regarding communication and the application of ACP as a standard element in palliative care practice. This program therefore seems helpful in training ID care professionals in the competencies needed for ACP.