(US Only) The Modified Accelerated Cost Recovery System (MACRS) is a form of accelerated depreciation enacted by the US Congress in 1981 and 1986. The depreciation system was introduced in 1981 as the Accelerated Cost Recovery System (ACRS). The intent of Congress was to encourage investment in depreciable assets by allowing accelerated depreciation—and thus larger tax savings in the early years of depreciable life.