The literature on alternative care focuses overwhelmingly on formal, court-orderedplacements; voluntary care placements are discussed less frequently. Least attentionof all has been given to informal kinship care placements, where a child is cared forby relatives but is not formally in the legal care of state authorities. In Ireland, theseplacements, when facilitated by state authorities in lieu of a care order or voluntarycare agreement, are known by professionals as ‘private family arrangements’. This ar-ticle explores evidence which shows that the use of such arrangements is motivatedpartly by a concern for subsidiarity, and partly by necessity: they provide a source ofplacements in cases where regulatory requirements and a lack of resources would oth-erwise make the placement challenging or impossible. However, this strategy carriessignificant risks. Private family arrangements receive less support and oversight fromstate authorities than formal care placements, and family members providing care un-der this model have no legal rights or responsibilities in respect of the child(ren). Thisplaces the child(ren) in a precarious position and raises concerns regarding a lack ofequity of care. The article will illustrate the impact of these concerns and make rec-ommendations for reform.