What depreciation method does MACRS require for buildings?

The Modified Accelerated Cost Recovery System (MACRS) requires the straight-line method for calculating depreciation on commercial and residential buildings. This method spreads the cost of the asset evenly over its useful life, which for buildings under MACRS is 39 years for non-residential properties and 27.5 years for residential properties.

Using the straight-line method under MACRS ensures that the depreciation expense is consistent each year and reflects a stable usage pattern of the building's value over time. This approach simplifies calculations and aligns well with the long-term nature of building investments. Other depreciation methods like declining balance, sum-of-the-years'-digits, and units of production apply differently and are not mandated by MACRS for buildings, making straight-line the correct choice in this context.