Music therapy is the highlight of four-year-old Kai Wall's week.

Kai is autistic and is non-verbal and his mother Mia Wall said music therapy brought together the work he did in occupational and speech therapy.

"What we've found is that he speaks more at music therapy," she said.

"It wasn't until we started going to music 12 months ago that we started to see him move forward.

"Music therapy seems, for him, to bring it together."

There are concerns for the future of this therapy and others such as art therapy under changes to the National Disability Insurance Scheme (NDIS) and the way the therapies are grouped.

The Australian Music Therapy Association (AMTA) said it discovered on Friday that the NDIS will remove music therapy from the Capacity Building — Improved Daily Living category.

NDIS Minister Bill Shorten said the changes mean the standard rate of $194 an hour will only continue to be fully covered for those who can show the therapies improve or maintain their "functional capacity".

Otherwise, clients will only be able to bill the scheme a "community rate" of $68 an hour and pay the rest out of pocket.

"I like art and music therapy, but we've got to make sure that it's in the best interest of the participant," he told Sky News.

In a statement the National Disability Insurance Agency (NDIA), which runs the NDIS, said the changes start on February 1 next year and providers can still charge a higher rate when they work with groups of four.

"While art and music therapy remain permissible, they do not meet the evidentiary standards required to be classified as a 'therapy' under the definition of NDIS supports," it said.

"Participants who have art or music therapy stated in their plan, because it is reasonable and necessary and based on evidence in their specific circumstances, can continue to access supports at the higher rate."

Music therapy providers at risk of shutting down, AMTA says

Practitioners are concerned it will increase costs for many clients, making businesses unsustainable.

AMTA president Monica Zidar said no-one in the music therapy community was consulted and the decision was made without justification.

"AMTA and its members hold grave concerns for NDIS participants who receive music therapy under this category," she said in a statement.

"We fear that the benefits they experience, and the goals they are working to achieve, will be jeopardised.

"We are also deeply concerned that participants' and registered providers' trust in the NDIA will be undermined.

"We know that this will cut over half of our funding, and it will make it impossible for families to access the support that they desperately need.

"We are aware of providers who have already put their staff on notice that if this doesn't get overturned, the providers will just be shutting down."

Calls to pause change and review decision

The decision also threatens the jobs of 950 registered music therapists in Australia, many of them registered NDIS providers.

The industry is calling on the NDIS to pause the change and review its decision along with providing its reasoning.

"We're actively requesting a meeting with Minister Shorten and the agency, so that we have the opportunity to provide the evidence that we have," Ms Zidar said.

Music therapist Grace Elliott said music therapy was a specialised allied health profession with a wealth of evidence behind its use.

"We do a two-year master's degree in order to be qualified to be a music therapist. We're a research-based profession," she said.

"What we do is we work with clients with disabilities that require our services to help them to achieve their everyday goals. So we are talking anything from physical goals to communication goals to social goals."

She said her work had supported a person with a brain injury to improve their gait and an autistic child connect with the world.

"The music is the thing that is powerful, that is motivating, and the thing that they come back for because it is rewarding," Ms Elliott said.

She said they were "devastated" by the NDIS decision.

"Our clients will lose a very effective therapy for themselves … and a lot of us have families that we have to support, and we are being told in less than a week's notice that our jobs are literally on the line," she said.

Music therapy a 'wonderful opportunity'

Ms Wall said she was shocked the decision was taken so suddenly and without consultation.

"It doesn't seem like it's a decision that's made based on factual information," she said.

"Parents that have got their kids that are using NDIS funding to do their music therapy either have to stop going to music therapy, or they're going to be in debt."

Ms Wall said she was concerned the decision was based on a lack of respect for the arts.

"The glint in [Kai's] eyes when he picks up the drumstick or he picks up the microphone trying to sing … it's a really wonderful opportunity for him," she said.

"It definitely helps him come out of his shell and connect easier."

The NDIA said the evidence base in relation to art and music therapy was "continuing to be developed, as it relates to disability-related support".

"In recognition of this the NDIA is referring art and music therapy to be assessed by the NDIS Evidence Advisory Committee," its statement said.