Small Corporations are exempt from the Alternative Minimum tax "if the corporation's average annual gross receipts for all 3-taxable-year periods ending before such taxable year does not exceed $7,500,000" ,Pasted from IRC Sec 55(e). What happens when the C corp., which has been exempt from AMT as a "Small Corporation", becomes an S corp.? Are only depreciable assets placed in service after electing Sub S subject to the AMT Post-1986 depreciation adjustment, or are all the depreciable assets subject to the AMT Post-1986 depreciation adjustment. . If a C corp. loses its status as a "Small Corporation" it is only the depreciable assets after that date that are subject to the AMT adjustment but I don't know what happens when a C corp. defined as a "Small Corporation" for AMT purposes becomes an Sub S.