In the UK, the average University graduate has £40,000 worth of debt. That's in stark contrast to the mere £3,500ish I had to pay back following my graduation in 1996. But in the UK, you only have to start repaying the debt once you start earning a certain threshold. Then, after a certain number of years (30 I think), they are cancelled in any case, regardless of how much there is left to pay.

In the US, are there similar conditions, or do you have to pay the full amount back regardless of time/income?