In case a student has a mixture of federal and private loans, then it is not advisable to consolidate them together. This is because the two kinds of loans will likely have different rates of interest.

Obviously, federal loans can be consolidated only after the student has come out of school. One condition is that the student must not be defaulting on payments and there is a minimum amount of loan that can be consolidated. In most states this minimum limit is $10,000. Consolidation of private loans has laxer rules, but then the expenses are higher.