The government added $5.3 trillion in new financial obligations in 2010, largely for retirement programs such as Medicare and Social Security. That brings to a record $61.6 trillion the total of financial promises not paid for.

This gap between spending commitments and revenue last year equals more than one-third of the nation’s gross domestic product.

Medicare alone took on $1.8 trillion in new liabilities, more than the record deficit prompting heated debate between Congress and the White House over lifting the debt ceiling.