With a buydown, the seller pays an amount to the lender so that the lender can give you a lower rate and lower payments, usually for an early period in an ARM. The seller may increase the sales price to cover the cost of the buydown. Buydowns can occur in all types of mortgages, not just ARMs.

Source: U.S. Department of Housing and Urban Development

A type of mortgage which requires the buyer to pay additional discount points or make a substantial down payment in return for a below market interest rate. Another form of a buy-down is one in which the seller offers 3-2-1 interest payment plans or pays closing costs such as the origination fee. During times of high interest rates buy-downs may induce buyers to purchase property they might otherwise not have purchased.

Source: Ginnie Mae