In 2013, Grace E. Elliott spent a night in a hospital in Florida for a kidney infection that was treated with antibiotics. Eight years later, she got a large bill from the health system that bought the hospital. This bill was for an unrelated surgical procedure she didn’t need and never received. It was a case of mistaken identity, she knew, but proving that wasn’t easy. Shelby Knowles for KHN hide caption toggle caption Shelby Knowles for KHN In 2013, Grace E. Elliott spent a night in a hospital in Florida for a kidney infection that was treated with antibiotics. Eight years later, she got a large bill from the…