If they meet Social Security's definition of disability they also must have worked long enough under Social Security to qualify for disability benefits.
Do you know what's the amount needed to get the 4 credits per year?
I don't
If an adult child is already receiving SSI benefits or disability benefits on his own record how would that affect the possibility of receiving benefits from their parents records?
They should check if they can get benefits payable on their parent's earning record to see if they can get higher benefits and if they are entitled to receive Medicare.
What if I have a child under the age of 18 with a disability?
In that case, we don't need to consider the child's disability when deciding if he or she qualifies for benefits as your dependent.
Is there any special situation in which a person can receive disability benefits?
Yes, there are situations other than the typical worker that qualify for the benefits on their own accord.
About qualifying for the benefit. What if my medical condition is severe and keeps me from doing basic work-related activities?