Other launch sites are planned for the ACT, the Northern Territory's Barkly region and in the Perth Hills area of Western Australia in mid-2014.
Labor did not regard the launch sites as trials for the scheme.
But Prime Minister Tony Abbott on Friday made particular note of how the sites are now described.
"You'll notice the language has changed," he told reporters following a Council of Australian Governments meeting in Canberra.
They are now "trials" and not "launch" sites, even though the scheme's website still uses the latter term.
The lessons learnt from the trial sites will be incorporated into the design of the final scheme.
Mr Abbott said the government was not going to pre-judge how the trials were going, but there was early evidence of higher-than-anticipated demand and costs.
Initial data shows the scheme's costs are running about 30 per cent higher than expected.
While the commonwealth, the states and territories all "absolutely" supported the scheme, there was a need to establish it on a sustainable basis, Mr Abbott said.
Earlier, Tasmanian Premier Lara Giddings raised concerns about the scheme's future.
It was too early to talk about the future of the NDIS because the trial sites had only been operating for about four months, she said.
"It needs to have at least 12 months before we get a firm idea as to how that model is working for Tasmanians," she told reporters, adding those benefiting from the scheme were loving it.
Labor had planned a July 2016 start date for a roll out of the full scheme and for it to be operational by 2019-20.
It is expected to provide support for 460,000 people with disabilities and cost federal and state governments about $22 billion annually.