Medicare Advantage is leading the U.S. government to spend billions more on seniors’ medical care than it should and needs a significant makeover, a nonpartisan watchdog said in a report to lawmakers. The program collected $12 billion in “excess payments” in 2020 over what the U.S. would have paid to cover people who used the private plans under standard Medicare, according to a report by the Medicare Payment Advisory Commission, or MedPAC, released Tuesday.