ACT Chief Minister Katy Gallagher and Disability Minister Joy Burch said about 500 jobs would move to the private sector in an overhaul of the territory's disability services, including a phased withdrawal of all government services in accommodation support, therapy services and early childhood intervention programs from the end of this year.

Government-provided services will move to private providers by 2017, giving participants the ability to choose the services they need using NDIS funding.

With provision for as many as 5000 people to be included in the NDIS, the changes will see an almost doubling of the ACT disability sector workforce. The growth will peak at $342 million by 2019-20.

Ms Gallagher said the ACT had learnt from implementation challenges in other states during the ongoing NDIS trial period and said members of the community would begin to receive information about the changes from Friday.

The ACT government will withdraw from specialist therapy by December 2016, from supported accommodation by June 2017, and from early intervention support services in territory schools at the end of this school year.

Public housing tenants covered by the NDIS would gain greater control over their lease arrangements, Ms Gallagher said. Properties currently administered by the ACT government will remain in public hands.

Ms Gallagher conceded some people would not welcome the change to services and employment conditions.

''We acknowledge … this will involve some change and that will be difficult, but nothing that we can't address together,'' she said.

Negotiations with the federal government are continuing over eligibility and start dates for the ACT.

Mental health care will not be affected by the plan.

"The NDIS will see an unprecedented level of investment in disability services in the ACT … and the growth in the disability sector workforce needs to be supported by growth in non-government service providers,'' Ms Gallagher said.

''Canberrans and particularly those who will be a part of this scheme should be assured that no person with disability currently receiving ACT government disability services will be left without support.''

A December 2012 deal between Ms Gallagher and former prime minister Julia Gillard committed the territory to provide the scheme for 5000 disabled Canberrans by this year.

Opposition NDIS spokesman Andrew Wall said the government had left the announcement until too late in the process and was yet to outline the cost of private services.

Health Services Union organiser Bev Turello said about 260 workers would be forced to compete in the private marketplace and standards of care could suffer.

"Our members have built up working relationships with their clients,'' Ms Turello said. ''They have regularly put their clients' welfare ahead of the their own.''