Beginning July 1, workers who use their car for business and don't get reimbursed from their employer will be able to deduct 55 1/2 cents per mile on tax returns. That's 4 1/2 cents more than the rate for the first half of this year.

The IRS says it is making the adjustment because of rising gas prices this year. Those who use their cars for medical or moving purposes will be able to deduct 23.5 cents per mile, up from 19 cents.  The mileage rate for motorists using their car for charitable works remains the same at 14 cents per mile.

These new rates will remain in effect until the end of the year. The IRS usually reviews the mileage rates in the fall for the next calendar year. The rate is determined by gas prices as well as depreciation, insurance and other costs. Businesses usually use the IRS figure to determine the rate at which they reimburse employees using their vehicles on the job.