Yes, the NDIS will typically approve funding for a pressure or hygiene mattress if you need it because of your disability.  They will assess the information you give them against the NDIS Funding Criteria. You will need to give them evidence or information that shows the mattress is a reasonable and necessary support.  Your Plan Manager and OT can work with you to achieve this. For more information, visit: https://ourguidelines.ndis.gov.au/would-we-fund-it/assistive-technologies/non-standard-mattresses