I'm guessing by income-based repayment plan you mean the IDR plans, which include several plans that determine hope payments in your income. I know. Confusing. IBR is one of those plans. The other must popular one is REPAYE. The type of plan you qualify for it most benefit from would be determined on several factors such as the original loan date, marital filing status on taxes, etc. Are these loans subsidized or unsubsidized? Even if you consolidate, the loan retains it's property of which portion has subsidized benefits. IBR and REPAYE have some excellent built-in benefits for interest, specifically for those borrowers that have payments that don't cover the interest. Usually those with low income would likely benefit from the loan forgiveness at the end, too, so the accruing interest may not even matter. One benefit of an IDR plan is that your interest will not capitalize. So let's say you have a particularly good month and you wanted to pay down extra, you could always do this without worrying that your interest is gathering interest. As long as you certify on time, it just sits there, separate of you interest-gathering principal. REPAYE's benefit is that for the first three years you're on the plan the government will pay all of your interest not covered by your payments. The remaining years it will cover half. For your unsubsidized loans it will cover half of the interest not covered by you payments up until forgiveness. IBR has a similar benefit, though it doesn't cover as much as REPAYE. Note that if you did start on IBR and switch to REPAYE your interest would capitalize and you have to make 1 different payment (you can request it to be $5) to switch plans. Your loan forgiveness count won't reset. Recently, my servicer decided to start also reporting accruing interest to the 3 CB. Despite my balances reporting at more than 100% utilization, it only has a small affect on your credit score. No more than having it maxed out anyway, and you'd have to make a huge dent in the loan to get any (small amount?) of points. In short, I wouldn't worry about it. I asked this forum and basically the loans won't stop you from getting 800+ eventually if you optimize other areas of your credit score. Are you going for the eventual loan forgiveness?
Edit: Subsidized loans: For the first three years you're on the plan the government will pay all of your interest not covered by your payments. The remaining years it will cover half.