43.6 Straight-Line Method

You may not use first-year expensing (Section 179 deduction), bonus depreciation, or accelerated MACRS (43.5) if your business use of your car, truck, or van is 50% or less in the year you place it in service. Mandatory straight-line recovery rates for business use of 50% or less using the half-year or mid-quarter convention are shown below. These straight-line rates are also used if your business use exceeds 50% and you elect straight-line recovery instead of the regular MACRS method. See the preceding section (43.5) for determining whether the half-year or mid-quarter convention applies.

For each year of the six-year recovery period, apply the straight-line rate from the applicable table against your unadjusted basis, which is the business part of your cost minus any first-year expensing deduction or special depreciation allowance (43.5). The deduction from the table is allowed only to the extent that it does not exceed the annual deduction ceiling (43.4).

If business use initially exceeds 50% and accelerated MACRS is claimed but business use drops to 50% or less before the end of the six-year recovery period, a recapture rule applies a straight-line computation retroactively (43.10).