Elias Anderson will be in the MCG crowd when his beloved Western Bulldogs take on Collingwood this Friday night, but he won't be able to see the players.

The 15-year-old has been in the same mechanical wheelchair for about seven years.

His parents have been trying to organise an adult-sized chair for two years that would allow Elias's body to be raised to eye level and enable him to watch the footy like everyone else.

Margie Anderson said the larger chair, worth about $40,000, would fit her son's growing body and help correct a developing spinal curvature.

Elias has outgrown his chair, making it a challenge to place his feet into the footrests. ( ABC Melbourne: Kristian Silva )

The Andersons said they had endured two years of bureaucratic hold-ups and red tape while their request sat with the National Disability Insurance Agency.

Elias's chair has broken down in recent weeks and parts of it are held together by duct tape. The joystick he uses to drive himself stopped working six months ago.

"Self-driving is one of the few ways for him to be independent, so not to be able to self-drive has taken away one of the last pieces of independence," Ms Anderson said.

"We're really concerned every time we go somewhere with Elias that the chair's going to break down."

Elias was born prematurely at 25 weeks and weighed less than 500 grams. He lives with cerebral palsy, an intellectual disability and several other physical conditions.

"Elias is fed by tube, so there's a lot of work involved in organising his feeds, setting up the feeding pumps and making sure everything's clean," his mother said.

"He can't walk or stand at all, so all of his personal care needs to be done by us."

Elias and his parents Craig and Margie are awaiting a decision on a new wheelchair. ( ABC Melbourne: Kristian Silva )

Ms Anderson said they first applied for a new chair in April 2017 when they contacted the Victorian Government-based State-wide Equipment Program (SWEP).

They were placed on a waiting list and told to try the National Disability Insurance Scheme (NDIS) when it was rolled out in western Melbourne last year.

After an NDIS plan was drawn up, it was sent to the NDIA's assistive technology team. Ms Anderson said they were still waiting to get approval five months later.

If the request is approved, it will take a further 12 weeks to build the customised chair.

In a statement, a spokeswoman for the NDIA said the agency "has contacted Elias's family to work with them to address their concerns".

"The NDIS rollout reached western Melbourne on October 1, 2018, at which time Elias was made eligible for the NDIS," she said.

"The NDIA continues to work with Elias's family to collect information from supporting allied health specialists to ensure Elias receives the necessary supports that best meet his needs.

"Elias's current plan includes funding to hire a power wheelchair as an interim solution while the NDIA works with his family to identify the most appropriate equipment."

Mother criticises NDIS funding

Ms Anderson contacted ABC Radio Melbourne after Prime Minister Scott Morrison told the station last week that "every demand for the NDIS is fully funded".

She said she strongly disagreed.

"We have people all over the place not getting what they need through the NDIS," she said.

"The reason we have people like Elias waiting for a wheelchair is because there's not enough staff in the offices or the NDIS is trying to pull back on how much spending they have."

This month's federal budget showed that funding for the NDIS in 2019-20 will fall by $3 billion.

The Government said the scheme had overestimated how much people would use NDIS services and would transfer funds to boost the hospital system.