Some disability service providers are looking after people for free until they can claim back-pay under the National Disability Insurance Scheme.
NDIS deputy chief executive Stephanie Gunn said there were about 2000 cases in which the necessary details to extend funding were not available, so carers were asked to keep looking after people until the claim and back-pay was approved.
"That is clearly not ideal for the providers," Ms Gunn told a Senate hearing on Thursday.
Ms Gunn said the shortfalls happened when someone's funding plan expired and the necessary details to extend it had not yet been collected.
She said providers were asked to keep up services on the understanding they would be paid once the funding was extended.
"We are very conscious that has an impact on families and particularly on providers," Ms Gunn said.
When the funding is approved, Ms Gunn said providers were able to claim for back-pay within a week.
