This is not an attack on what anyone here has said I just wanted to clear up some possible misconceptions. I hear a lot of talk on SDN stating that IBR or PAYE are great options if you're debt loads are really high, as is the case with some of the most expensive private schools where students typically take out over $500K+ in principal on their loans (this doesn't include interest that accrues while you're in school.) It seems like a great plan at first. I can pay only 10% of my income for 20-25 years and all of my remaining debt will be forgiven, that way my huge debt load really won't pose a substantial financial threat. I just wanted to point out that after 20-25 years any remaining debt, while it will be forgiven, will be taxed as income. So, lets say a student who takes out $500K in student loans graduates and is making $150K salary right out of dental school (a generous estimate.) That student would be paying approximately $15K a year in repayment. But, we can't forget to take interest into account. On a $500K note at an average interest rate of 6.34% (an average of the two federal interest rates) your loan will accumulate $31.7K in interest the first year. So, you pay down $15K of that interest and the loan increases $15.7K the first year. But, because you pay interest on your interest the loan increases each year. Basically by the end of a 20 year period your will loan will now have increased to ~$1.15 million. This would be fine if the loan was truly "forgiven" but its not. You have to pay income tax on that money. So if you made $150K the year you made your last payment you would've made (as far as the IRS is concerned) $1.3 million that last year. Lets be very generous (especially with the prospect of tax increases that Sanders is proposing) and say you only pay 33% tax on that money. You would now be the proud owner of a $429K note due to the IRS at the end of your 20 year period, ending up with almost as much as you originally took out in principal. And I am guessing the IRS is far less accommodating than Federal Student Aid will be.
Here's the link stating that any forgiven balance will be taxed as income (question 25 at the end of the paragraph):
https://studentaid.ed.gov/sa/sites/default/files/income-driven-repayment-q-and-a.pdf
Here's an amortization sheet I created showing the buildup of the interest