Medicaid is (1) not available to anywhere close to all poor people in the US (though it would have been for a particular poverty definition had ACA expansion been universal), and (2) doesn't provide free care to all the poor people to whom it is available (both premiums and cost sharing—effectively, deductibles—are allowed in State Medicaid plans), and (3) very often does have limits on available services, so while Medicaid exists, it does not meet the description made of healthcare being free in the US if you are poor without treatment restrictions that has been made.
Medicaid is (1) not available to anywhere close to all poor people in the US (though it would have been for a particular poverty definition had ACA expansion been universal), and (2) doesn't provide free care to all the poor people to whom it is available (both premiums and cost sharing—effectively, deductibles—are allowed in State Medicaid plans), and (3) very often does have limits on available services, so while Medicaid exists, it does not meet the description made of healthcare being free in the US if you are poor without treatment restrictions that has been made.