Unanderra quadriplegic Richard Kramer will lose more than 200 hours of personal care each year under changes to disability support required by the National Disability Insurance Scheme.
That is an average of four hours less care a week once the 51-year-old switches from the state government's attendant care program to its community support program on July 1.
Mr Kramer said he was devastated that his parents, Heather and Brian Langlands, would have to take up the slack.
"With my attendant care package, I had a guaranteed 35 hours of care a week and administrative costs were included," he said.
"The community support program is a dollar-based program and because I will have to pay more than $10,000 for administrative costs, then I've had to sacrifice hours of care.
"My mum's 69 and my dad's 80 next month. They've been caring for me for 31 years since my accident.
"Even with current care, they still have to care for me for around 130 hours a week. I don't think it's fair they'll have to do more."
Mr Kramer broke his neck after he dove off a bridge into Minnamurra Rivulet 30 years ago.
Mrs Langlands said she would be forced to place her son in a nursing home if the home care was insufficient, or unsafe.
"The loss of care will result in services having to be rushed and my husband and I will have to take up the burden," she said. "We are not young any more. We can't do as much as we once did."
Mr Kramer said: "We were told that no person was going to be disadvantaged by transition to individualised funding leading into the NDIS, but already I am being disadvantaged."
Albion Park Rail quadriplegic Ken Wynn also stands to lose in the transition between programs.
The 62-year-old does not want to shop around for a cheaper, and possibly inferior, service provider so he will give up weekend care.
"I've been in a wheelchair for 47 years after suffering spinal injuries in a work accident at 15.
"There were no services around then. I was one of the founding members of Spinal Cord Injuries Australia and we fought hard for the care we now receive.
"Now that care is being scaled back again. Because I'll be around $20,000 in the red, due to the administrative costs I'll have to pay, then I'll lose six hours of care a week."
Minister for Disability Services John Ajaka told the Mercury: "I understand Ageing, Disability Services and Home Care is working with these clients to discuss their concerns. I requested the agency keep me informed about how they are resolving these concerns."