Many people would qualify for CHIP. But of course that only applies while they are children. If they are disabled, then they would likely qualify for social security and medicaid as adults depending on the severity type. The real issue is that they may need help with the administration of the benefits or with things not covered after the parents pass away.
Social security disability is incredibly difficult to live on. Depending on the individual's work history it can pay as little as $700/month. The average beenfit is $1263 but it's only that high because most people claiming it became disabled but had (or their spouse had) a productive work History before that. People with lifelong disabilities will be well below that.
You can supplement with part-time work but that only gets you so far. As soon as you start making money on disability, you lose 1 dollar for every two. And the most you can make is $1260/month. At that point you lose Medicaid and any progress you've made is lost because insurance is way more than you are making.
You effectively top out at $1263 + $1260/2 = $1893/month. Rent is going to claim 1/3 to 1/2 that.
Yes, US disability and far too many government benefits are setup in a way that can actively discourage people from self improvement or trying harder.
Where are the fade outs, and the incentives that will reward you for getting off the system, rather then punish you? It's a subject for a different thread at a different time.
Most serious medical costs will far outstrip the increased salary. Usually you use that increased salary to pay some crazy insurance premiums/deductibles.
Yes and no. Acute health care may be free in Canada, but even here, money has a particularly substantial effect on your quality of life if you're disabled.