An adjustment that is to be made to swap pricing to take account of the off-market requirements on a counterparty to a swap. The present value differential between an at-market swap and the required off-market swap should be determined so the counterparty with the greater present value would pay the differential to the counterparty with the lesser present value.

In case the swap coupon in the off-market swap is below that in the at-market swap, the payment of that present value differential is known as a buy down.