A computer programming error led the Centers for Medicare & Medicaid Services to miscalculate financial penalties against hospitals that have high rates of patients returning within 30 days. The Hospital Readmissions Reduction Program, established by the 2010 health care law, kicked in Monday, with 307 hospitals losing 1 percent of their regular reimbursements. Medicare published a list of the penalties in August. But on Friday, the last workday before the penalties started, Medicare published new rates after discovering it inadvertently included data in its calculations that were too old. As a result, 1,422 hospitals are getting hit with slightly higher penalties, while 55 hospitals are getting slight reprieves. A total of 2,217 hospitals will lose some money.