Transfer of development rights (TDR) programs enable the transfer of development potential from one parcel of land to another. TDR programs are typically established by local zoning ordinances. In the context of farmland protection, TDR is often used to shift development from agricultural land to designated growth zones located closer to municipal services. TDR is also known as transfer of development credits (TDC) and transferable development units (TDU). This fact sheet provides basic information about TDR programs and tracks the amount of agricultural land protected by TDR programs nationwide.