About one quarter of all health care spending in the U.S. is waste, according to a new study released in JAMA last week. The estimated cost ranged from $760 billion to $935 billion from January 2012 to May 2019. What is driving the numbers? Waste is mostly due to failure of care delivery, failure of care coordination, over treatment or low-value care, pricing failure, fraud and abuse, and administrative complexity. The lead author was William Shrank, Humana's chief medical officer. He and his colleagues say the waste is paid for through higher premiums, out-of-pocket spending, and taxes.