Providing medical care and services to the 9.7 million U.S. residents who are eligible for both Medicaid and Medicare results in mismanagement and unnecessary spending, according to some federal health officials. Melanie Bella, a CMS official who oversees the two programs, said Medicare and Medicaid were "never designed to work together." Meanwhile, other officials and health care professionals say it is common for the two programs to shift patient costs to one another, raising overall spending.