The Budget provides $23 million a year to pay carers who look after a disabled family member aged 18 or older who is assessed as having high or very high needs.
This is the Government's response to the case brought by eight families seeking payment, which the Crown lost in the Court of Appeal last May.
Mr Ryall said, "Our society expects parents to care for and support their dependent children. But the Court of Appeal ruled that this 'social contract' does not extend to continuing to care for adult sons and daughters who have a lifelong disability."
The Ministry of Health expects the scheme will apply to around 1600 disabled people with high and very high needs.
Those assessed as eligible can employ a family carer to provide personal care and household management or continue to use a commercial provider.
Asked to explain the high and very high needs eligibility criteria, Mr Ryall's office gave as one example a person having motor neuron disease or muscular dystrophy and needing a powered wheelchair and a high level of personal care.
Carers Alliance chairman John Forman welcomed the new scheme, which he said was a significant step forward. But many affected people would be disappointed that the pay rate was so low.
"They should at least pitch it at a level that's being paid in those agencies that provide community-based disability support."
Mr Forman said there would also be disappointment that spouses and partners of disabled people were specifically excluded from the scheme.
"I don't think many people think that's very fair at all. I think it will be a major point of contention."
The ministry said it would "explore" later this year the extension of the scheme to family carers of adults with chronic health conditions, "as the family care expectations and impacts for this group are similar to adults with disabilities and their family carers".
One of the families in the litigation, now back at the Human Rights Review Tribunal for settlement, is the Robinsons from near Thames. Cliff, aged in his 70s, is a father and caregiver to two intellectually disabled children, Marita and Johnny, both in their 40s. Johnny also has schizophrenia and diabetes.
Mr Robinson took the children out of homes when they were toddlers and has cared for them since.
"What would cost the Government less," he has asked, "paying parents as caregivers, or meeting the cost of institutional care full-time for their children?"
Health
• People who care for a disabled adult family member can be paid by the Government.
• But not if the disabled person is their spouse or partner.
• Scheme starts on October 1.
• Disabled person's needs must be assessed as high or very high.
• Carer gets minimum wage, $13.75 an hour.
• Maximum of 40 hours' pay a week.
• Estimated cost to Government, $23 million a year.