GOP targets Lew over Medicare spending

Whenever the Medicare trustees issue a warning about Medicare's finances as part of their annual report on the program, the president is legally required to send Congress a proposal for curbing Medicare's spending. 

Obama hasn't issued those proposals in response to the trustees' reports, although his annual budget proposals have outlined hundreds of billions of dollars in Medicare savings.

Lew, who is now White House chief of staff, would become chairman of the Medicare trustees if he is confirmed to lead Treasury. Republicans said he was responsible for meeting the requirements of the Medicare warning in his earlier role as White House budget director.