Depreciation of property other than real property begins in the middle of the quarter in which it is placed in service when more than: 25% of the total cost of all depreciable property placed in service during the year occurs during the fourth quarter. 40% of the total cost of property less any Sec. 179 deduction placed in service during the year occurs during the fourth quarter. 40% of the total cost of all depreciable property placed in service during the year occurs during the fourth quarter. 25% of the total cost of Sec 179 property placed in service during the year occurs during the fourth quarter