Background: Although a 'person-centred focus' is a legislated objective for both aged-care and disability services sectors in Australia, evidence suggests limited translation into systems and practices due to entrenched silos. This paper proposes a Best Practice Framework to mitigate these silos. Methods: Mixed-methods research comprising key informant interviews with major stakeholders across both sectors; a survey of people with/without intellectual disability aged 60+ years; qualitative in-depth interviews; and survey of health professionals. Results: There is an urgent need to develop inter-sectoral 'integrated care systems'. Key components include choice in accommodation; regular assessment of health and well-being indicators; development and adoption of nationally consistent policies/standards across integrated aged- and disability-care sectors; improved strategies for workforce planning; and upskilling of existing staff including place-based collaboration. Conclusions: An integrated service model requires collaboration on broader public policy instruments, appropriate planning and resourcing. A strategic shift is required to ensure better quality person-centred support systems.