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.