No. Your extra payments already did the paydown, so no additional lump sum is needed to recast. A recast is your servicer re-amortizing the existing loan over the remaining term at the current, lower balance, which lowers the required monthly payment. People usually pair a recast with a lump-sum principal payment, but if you have already made large principal reductions, that step is done. You simply request the recast. Two caveats: - Servicers are not obligated to grant one. Most will, but it is not guaranteed, there may be a fee, and some loan types (government loans, for example) generally are not eligible. Call your servicer to confirm their process before you count on it. - The lower payment does not happen on its own. Extra principal payments shrink your balance and total interest, but the required monthly payment stays the same until you specifically ask for a recast. A recast keeps your existing rate and term while shrinking the payment, which makes it a different tool from a refinance. Ask for it by name.