Disability Minister Tony Piccolo says NDIS funding to SA still not determined Premier Jay Weatherill, left, at the Council of Australian Governments (COAG) meeting in Canberra. SOUTH Australia does not know the full cost of the National Disability Insurance Scheme deal it has done with the Federal Government and is still waiting on key details of the services the program will provide. Premier Jay Weatherill last week "agreed to the full implementation" of Prime Minister Julia Gillard's multibillion-dollar scheme from 2018, a day before the COAG meeting in Canberra. He said annual disability funding from the State Budget would rise from the current $345 million to $723 million in 2018. Disability Minister Tony Piccolo yesterday confirmed to The Advertiser that funding would have to be incrementally increased in each Budget to deliver full implementation, but amounts had not yet been determined. It exposes the Budget to the risk of hundreds of millions of dollars in extra costs as revenue also declines. "A heads of agreement is being drafted and is not currently available," Mr Piccolo said in a statement. Rules for access to the scheme and support for participants are currently being finalised. Opposition Leader Steven Marshall said that he "strongly supports" the NDIS but he feared Mr Weatherill had made a public funding pledge for political purposes without examining critical policy details. "We wonder whether saying publicly that the state is signed up lock, stock and barrel to the NDIS before the final details have been released was a good negotiation strategy for South Australia," Mr Marshall said. State NDIS levels are based on expected demand for the scheme. SA must pay 25 per cent of overruns if spending blows out after 2018. However, rules on what the scheme covers will not be finalised until next month. SA Council of Services executive director Ross Womersley said a disability funding injection would be welcomed by people seeking more independence but important details were missing. "While the money is incredibly important and welcome, it's equally important that we make sure the way it gets spent really does lead to change in the way people live their lives," he said. The last thing we want is a whole lot more money in the system but people getting the same old same old. An NDIS "trial site" is due to begin operating in SA from July 1 this year. Mr Weatherill will hand down his first Budget as Treasurer on June 6.