The Internal Revenue Service announced an increase in the optional standard mileage rates for the final six months of 2011. In recognition of recent gasoline price increases, the IRS made this special adjustment for the final months of 2011. The IRS normally updates the mileage rates once a year in the fall for the next calendar year. Taxpayers may use the optional standard rates to calculate the deductible costs of operating an automobile for business and other purposes.

The rate will increase to 55.5 cents a mile for all business miles driven from July 1, 2011, through Dec. 31, 2011. This is an increase of 4.5 cents from the 51 cent rate in effect for the first six months of 2011, as set forth in Revenue Procedure 2010-51. The new six-month rate for computing deductible medical or moving expenses will also increase by 4.5 cents to 23.5 cents a mile, up from 19 cents for the first six months of 2011. The rate for providing services for charitable organizations is set by statute, not the IRS, and remains at 14 cents a mile.

The optional business standard mileage rate is used to compute the deductible costs of operating an automobile for business use in lieu of tracking actual costs. This rate is also used as a benchmark by the federal government and many businesses to reimburse their employees for mileage. Taxpayers always have the option of calculating the actual costs of using their vehicle rather than using the standard mileage rates.