As a clinical pharmacist in a large trauma center county hospital in the US I can attest that we "give away" most of our drugs when it comes to homeless or those without helthcare. We ask for payment, but the ability to pay has no bearing upon our requirement to provide care. This is the same in all of the county hopital inpatient or out patient clinics.
The tax and spend philosophy is not the answer. The 40 million un-insured still have the best health care in the world... and it is FREE.