College students are facing a roughly $20 billion increase in the cost of their federal loans, despite a much-heralded deal in Washington to contain the expense of higher education. Starting Sunday, students hoping to earn the graduate degrees that have become mandatory for many white-collar jobs will become responsible for paying the interest on their federal loans while they are in school and immediately after they graduate. That means they'll have to pay an extra $18 billion out of pocket over the next decade. The costs of full-time graduate students. Banter between the president and members of Congress at an annual dinner tonight could get a bit uncomfortable. Meanwhile, the government will no longer cover the interest on undergraduate loans during the six months after students finish school. That's expected to cost them more than $2 billion. These changes have received little attention as lawmakers instead focus on preventing a spike in interest rates on federal student loans. They are the fallout of earlier political battles and compromises over broader issues such as the federal budget and the national debt ceiling. And they are forcing students such as Clarise McCants to make tough choices about how to pursue academic goals without jeopardizing financial security. "I don't want to hastily make a decision that could waste thousands of dollars I don't have," said McCants, who said she will have to put off graduate school after finishing her undergraduate degree at Howard University in the spring. That could kind of prove disastrous for my finances. Much of the recent debate about the nation's soaring student debt burden has centered on how to prevent the interest rate on new federally subsidized undergraduate loans from doubling to 6.8 percent on Sunday. President Obama made the issue part of his stump speech at colleges nationwide, while Republican rival Mitt Romney also came out in support of the measure. This week, Senate leaders announced that they had finally reached a compromise on how to pay the estimated $6 billion cost of freezing the rate for one year. Congress is expected to approve the deal by Friday. But the deal's benefits are being blunted by the two changes that will saddle students with higher costs. Lawmakers ended a long-standing program that pays the interest on federally subsidized loans for six months after a student graduates from college. The change applies to new loans issued through July 2014. Students who take out these loans over the next year will receive the lower interest rate - but that amount will be charged to their bill as soon as they throw their graduation caps in the air. Students who apply for federal loans next year will be hit with a double whammy: a higher interest rate that begins after graduation.