After Medicaid expansion, Medicaid is offered to those with an income of below ~130% of the federal poverty line: roughly $16k a year for an individual. I think we'd both agree that $16k/yr is abjectly poor, and those making even 50% more than that are still very poor.
However, only 33 states have expanded Medicaid. Some of the poorest states in the Union have not expanded Medicaid. Therefore, Medicaid is still strictly for disabled population under a certain income in those states.
To say poor people get free healthcare in the US isn't a true statement. Some very poor people in the US have access to Medicaid, depending on their location and income. Some poor people in states that have expanded Medicaid will still not get free healthcare because, while they are objectively poor, they do not meet the income requirements for Medicaid.
For those with a low income, and without access to Medicaid, health insurance premiums are very high and have deductibles that people would need to take a car loan out to pay.