NDIS participants being exploited by unfair price hikes can now report price gouging to a new taskforce.

The federal government has launched a crack down on illegal overcharging, led by the Australian Competition and Consumer Commission, which will be able to investigate providers who impose an "NDIS 'wedding tax'" and jack up prices just because someone is on the National Disability Insurance Scheme.

NDIS Minister Bill Shorten vowed to put "shonky" providers who extorted people with a disability out of business, saying some people had made themselves millionaires by rorting taxpayer funds for disability services.

The Australian Criminal Intelligence Commission estimated as much as a fifth of all NDIS expenditure was rorted.

Mr Shorten said participants and their carers, guardians and nominees would receive letters from this week explaining their rights and how to "fight back" against providers who overcharge.

"The era of ripping off disabled people on the NDIS is over," Mr Shorten said.

"Charging you more just because you are simply an NDIS participant is wrong and it is a breach of federal law. We have upgraded the NDIS rules to make it clear overcharging is prohibited and we have further legal changes coming to more strongly prohibit and punish such practices."

Consumers will be able to report to the taskforce, which will then assess complaints and launch an investigation where a participant may have been overcharged.

While the ACCC does not normally consider individual price complaints, the new code of conduct for NDIS providers obliges them not to charge a higher price for goods for a participant "without a reasonable justification" — so the consumer watchdog could determine a provider has breached the code.

Providers who are found in breach face financial penalties and permanent bans, as well as criminal sanctions where fraud is suspected.

People with Disability Australia president Marayke Jonkers said NDIS participants should feel confident they are getting value for money.

"These changes will help end the practice of charging us more for the same service simply because we’re on the NDIS while putting the onus on the providers to do the right thing," Ms Jonkers said.