Medicare is making my grandma pay $581 a month as a deductible towards doctor visits and medications. Why is there no consideration for her rent she has to pay?

Until her assets are nearly used up, she is considered private pay. Medicare Part A doesn't likely have a premium, but Medicare Part B and any supplemental policies (these cover doctor visits, etc. while Part A is more for hospitalization) carry a premium. Until any of us have used up most of our money, including savings, we pay these premiums and co-pays, plus a separate Medicare Part D policy for drugs (if we choose). Once most of the assets are gone, then people can qualify for Medicaid, which is for the poor and won't carry premiums.

I know, it's hard. I've been there.
Carol