That was one of the arguments for the ACA. Hospital emergency rooms are a very expensive way to treat minor problems, and an very ineffective way to treat chronic ones. This is why each homeless person in SF costs the medical system about $10K a year.

Prior to 1986, hospitals were not required to treat the uninsured, but most nonprofit hospitals did anyway.[1] For-profit hospitals tried to dump them on nonprofit and charity institutions. The 1986 law makes all hospitals that take any Federal funding treat uninsured people with emergency conditions.

[1] https://en.wikipedia.org/wiki/Emergency_Medical_Treatment_an...