Scammers are preying on disabled people and their carers, asking them to pay a fee to join the government's national disability insurance scheme (NDIS).

The scheme hasn't launched yet but when it does, in July, there won't be any need for people to pay administration fees, Disabilities Reform Minister Jenny Macklin says.

"People should be very wary of anyone asking for payments for government schemes, including the NDIS," she said in a statement on Monday.

The NDIS Launch Transition Agency will be contacting people with disabilities in the trial sites in coming months to let them know about the scheme.

But its staff won't be asking for fees from anyone.

Ms Macklin said people concerned that their privacy had been breached by the scammers or who had revealed personal information during one of the scam calls should contact police.

For further information, email helpdesk.fraud@fahcsia.gov.au.