This article examines the legislative frameworks for advance healthcare planning in England & Wales (the Mental Capacity Act 2005) and in Ireland (the Assisted Decision-Making (Capacity) Act 2015), undertaking a comparative analysis of each measure, with particular focus on the detail of the approaches taken. It is only through this kind of detailed focus that the normative choices made by legislation can fully be understood and evaluated. The article argues that, in several respects, possibly because the drafters were able to reflect lessons learned from other jurisdictions, the Assisted Decision-Making (Capacity) Act 2015 provides a more rounded and complete form of advance healthcare planning than that provided by the Mental Capacity Act. This is on the basis that it provides more protection for patient choice; better potential for delivery on the choices made; and a more appropriate balance between formalities and enforceability.