Australia's children with developmental delays such as autism aren't getting equal access to the multi-billion-dollar National Disability Insurance Scheme (NDIS).

An analysis by the ABC of hospital records indicates that postcode discrimination is rife, with families in poorer areas waiting hundreds of days to get the diagnosis that is critical to getting into the NDIS.

Children should have to wait no longer than three months to get a developmental assessment to find out the underlying cause of developmental delays, according to Australian and international guidelines.  But children using Campbelltown Hospital in New South Wales typically have to wait a year before getting an appointment with the assessment team.  At least two waited for more than 600 days.

An hour away in the more affluent Sydney Children's Hospital at Randwick, the waiting is reduced to as little as two months, ten months at the latest.

"It's a form of developmental apartheid," federal Labor MP and paediatrician Mike Freelander.  "Most people would want an equitable NDIS, but we've allowed it to develop, and in a way we've allowed the health system to develop, where your health outcomes and your developmental outcomes depend on your postcode," he continued.

Waiting too long to get the assessment could condemn as child to "start school really behind their peers and that can lead to long-term problems both in terms of academic outcomes and behavioural outcomes," said Dr. Freelander.