- What is the interest? It does it? Does it very? Is the reset amount there? There's there's a set amount of interest per month per payment, okay? And there's a there's an installment agreement fee that you have to pay just to get set up into an installment agreement of $120. The interest gets spread out over 72 months, so you're paying six years of interest on a debt liability from maybe that stems from one or two years of liability. It's not a good plan, and the IRS wants taxpayers to go into that plan because obviously it's very profitable for the IRS to get people into installment agreements.