If you do not pay your student loan then your cosigner must pay it. If she does not pay it then it will be reported as a defaulted obligation on her credit report and it will harm her credit rating severely. Student loan debt will not likely go away as a result of your bankruptcy, as the previous poster pointed out. Whoever told you it would has given you bad information. But even if it was, say, a car loan the impact on your sister would be the same. Just because you file bankruptcy does not relieve your sister of her promise to the creditor that she would make good if you don't pay. That promise is what induced them to make the loan, and it is her independent obligation.