The rollout of the National Disability Insurance Scheme in Western Australia has been pushed back to mid-next year - 12 months later than the rest of the country - but the trials will be expanded.
The federal and WA governments created a comparative trial of two NDIS models in 2014.
The WA NDIS, formerly known as NDIS My Way, which is currently delivered in the lower southwest and Cockburn-Kwinana areas, will be expanded from October 1 to the local government areas of Armadale, Murray and Serpentine-Jarrahdale.
From January 1, the National Disability Insurance Agency model in the Perth Hills will be expanded to Bayswater, Bassendean, Chittering, Toodyay, York and Northam.
Federal Social Services Minister Christian Porter said the expansion of the two trials would allow an additional 2700 people to access the NDIS in WA until the final model is finalised later this year.
"This will be informed by the comparative evaluation and will be done in consultation with people with disability, their families, carers and service providers," he said.
Mr Porter denied the delay was due to the state and Commonwealth not agreeing to a single scheme.
"When the coalition inherited government, there was no agreements with WA put in place at all, so we were working from an absolute baseline of zero," he told reporters.
"What we have now is a clear timeline for when agreements will occur but the reality is things in Western Australia will be a little bit more tailored and bespoke."
State Disability Services Minister Donna Faragher said WA had a fantastic disability services sector to build on.
"I think we can get a model which has local control but with all of those other mechanisms we need to have in terms of governance, eligibility and portability so we are the same as the rest of the country."
© AAP 2016