Background: This study investigated the extent to which behaviour support services are accessible under Australia's National Disability Insurance Scheme (NDIS). Method: We conducted semi-structured interviews with families who support a member with an intellectual disability and challenging behaviour. We analysed this data with a supply and demand access framework initially designed for health care and described the lived experiences of participants and their families accessing behaviour supports. Results show that while the NDIS has improved participants' ability to pay for behaviour (and other) supports, this financial capacity represents only one of six other important aspects of access. Results: Families compensate for the shortcomings of the marketised environment which has arisen under the NDIS. Conclusion: This raises questions about the responsibilities of support provision, which is obscured in the new NDIS system and places responsibility for successfully accessing behaviour supports onto the family of the person with an intellectual disability.