Fyi it takes 6+ months to get on SSI or SSDI and you can't make gainfull employment income for those 6 months then if you get approved you have to wait 2 years to get Medicare. As for Medicaid it depends on the state you live, and is also income based determined. So for someone working while receiving cancer treatments they have to rely on their employer, or private insurance coverage, while in the process of trying to qualify for social security disability or Medicaid. The only instantly approved reason disability gets approved is if the doctor tells them a person has end stage renal failure, or has a illness that will end in death. Still it's not a instant determination that happens in a week, it takes months. And as for Medicaid goes, some states have stricter requirements than others. It depends on how many assets a person owns, and how much money is in the bank. Medical treatments cand eat that all up in a hurry. But still people with cancer don't automatically qualify for Medicaid.