"Social Security revenue became insufficient to pay full benefits, beginning in 2010. The government had to borrow $49 billion that year, in order to pay full Social Security benefits. In 2011, $45 billion had to be borrowed to cover the gap between revenue and the cost of paying full benefits. The gap between revenue, and the cost of paying benefits, will get larger and larger, as time passes, and the Social Security trustees estimate that the gap will be a whopping $318.7 billion in 2030."
Social Security's financial problems
"Cash Flow Imbalance: Social Security's dirty little secret" Allen W. Smith