New figures predict an even larger NDIS cost blowout than many expected. 

The National Disability Insurance Scheme (NDIS) is facing a financial challenge with projections indicating its annual cost could reach $125 billion by 2034, significantly higher than the Albanese government's target of $95 billion set in last year's budget. 

This cost represents nearly 3 per cent of the gross domestic product, underscoring the scheme's growing financial burden.

Government actuary analysis reportedly suggests the NDIS has underestimated its scale, with current support extending to over 610,000 people and costs expected to be $42 billion this financial year. 

Participant numbers are predicted to double to 1.2 million in a decade, a figure considered conservative by government actuary Guy Thorburn. 

He highlights a 22 per cent expected increase in child participants with developmental challenges, suggesting future costs may exceed current projections.

The lifetime cost of the NDIS is estimated at $1.4 trillion, with an average of $2.63 million per participant. 

Despite budget measures aimed at capping growth at 8 per cent by mid-2026, Thorburn expresses doubt about their sufficiency, emphasising the need for sustained efforts over a decade.