Background: Improved life expectancy means that more adults with intellectual disabilities are now living with ageing parents. This study explored older families' perceptions of the future. Methods: Semi‐structured interviews were conducted with nine older parents and three adults with intellectual disabilities and analysed to produce an explanatory thematic framework. Results: ‘Tolerating uncertainty’ was the major theme in participants' attempts to manage anxieties about the future, encompassing sub‐themes of ‘accepting the parenting role’, ‘facing challenges’, ‘being supported/isolated’, ‘positive meaning making’, ‘re‐evaluating as time moves on’ and ‘managing future thinking’. Some participants expressed preferences for their future which were in contrast to their parents' views, and provide a unique perspective that has often been neglected in prior research. Conclusions: This research has found commonalities in how families tolerate the uncertainty of the future, but also unique differences that require tailored interventions and prospective action by services.