NOTE: The information in this post is true for the state of Michigan. Medicaid rules vary from state to state.
There are lots of great things about Medicaid--it has medical, vision, and dental coverage; low copays; you can apply for it at any time; and you can use it as a secondary insurance.
What does this mean?
Imagine that you have an employer insurance plan, but it has a high deductible, and you have to pay out of pocket for your first $3,000 before the insurance will pay anything. If you are Medicaid eligible, Medicaid will be the second insurance (that means that your employer insurance gets billed first), and Medicaid will pick up what the employer insurance doesn't cover.
Medicaid as a secondary insurance can significantly reduce your bills!
There are some other benefits, too. For instance, you may have good medical coverage, but no vision or dental coverage. As secondary insurance, Medicaid can pay vision and dental benefits.
Just note: Medicaid cannot be secondary insurance for any Marketplace plans. If you are eligible for Medicaid, you cannot get subsidized Marketplace coverage. But if you have employer coverage, sometimes Medicaid as a secondary insurance can be very useful.