That’s how much Congress would have to put in an interest-bearing account today to cover the gap between the Social Security and Medicare benefits it has promised, and its ability to actually keep those promises.

The trustees of the Medicare and Social Security programs released their annual reports at 3pm today.

A brief rundown:

The unfunded liability of the Social Security program grew by 20 percent (from $12.8 trillion to $15.3 trillion) while Congress dithered over reform proposals.

But the Social Security gap is still smaller than the unfunded liability of just the Medicare prescription drug program, which weighs in at a robust $16.2 trillion.

The total unfunded liability of Medicare topped $70 trillion (It’s actually $70.8 trillion. Round up or down to suit your taste.)

The trustees’ estimate of the unfunded liability of the Medicare drug program actually shrank 11 percent from their 2005 estimate of $18.2 trillion. But that reduction was more than offset by a 2 percent increase in the unfunded liability of the physician insurance part of Medicare (from $25.8 trillion to $26.2 trillion) and a 16 percent surge in the unfunded liability of the hospital part of Medicare (from $24.4 trillion to $28.4 trillion).

All told, Medicare’s problems are over four times the size of Social Security’s.