For 2018 through 2025, the miscellaneous itemized deduction for investment-related costs is not deductible. Before 2018, these amounts were subject to the 2%-of-adjusted-gross-income floor. After 2026, such amounts may be deductible (assuming total costs exceed the 2% floor).
A rapid depreciation method determined by a constant percentage based on useful life and applied to the adjusted basis of the property.