The National Disability Authority's mandate is set out in the National Disability Authority Act 1999, with additional functions assigned under the Disability Act 2005, both of which are detailed in the appendix.

The overarching mandate of the National Disability Authority is, in summary, to provide advice and information to the Minister on matters concerning policy and practice in relation to people with disabilities and to assist the Minister in the co-ordination of disability policy. In doing so, the National Disability Authority has functions in relation to: research; assisting the development of standards; producing codes of practice; monitoring implementation of standards and codes of practice and recognising the achievement of good standards and quality, including through the provision of a disability equality awards system. The National Disability Authority has responsibility for monitoring the employment of persons with disabilities in the public sector.

The National Disability Authority operates the statutory Centre for Excellence in Universal Design, promoting the design of the built environment, products, services and information and communications technology, so that they can be accessed, understood and used by all persons regardless of their age, size, ability or disability. The universal design role, while including disability, also extends beyond disability to consider design issues for all citizens, engaging with standards bodies, industry, professional bodies and educational institutions.