A bipartisan group of senators introduced legislation on Thursday to make Medicare take the financial status of hospital patients into account when deciding whether to punish a hospital for too many readmissions. The bill attempts to address one of the main complaints about the readmissions program: that hospitals serving large numbers of low-income patients are more likely be penalized. Over the past two years, the federal government has reduced payments to two-thirds of the nation's hospitals because they have high numbers of patients becoming ill and returning after being discharged.