Notice 2013-80 provides the standard mileage rates that apply starting January 1, 2014. The good news is gas prices have been dropping, the not-so-good news is the standard mileage rate will be dropping also. The mileage rates for use of a vehicle in 2014 will be:
56 cents per mile for business miles driven
23.5 cents per mile driven for medical or moving purposes
14 cents per mile driven in rendering services to charitable organizations
The rates for business, medical, and moving are 0.5 cents per mile below the 2013 rates, reflecting the results of an independent annual study of the costs of operating an automobile. (The rate for charitable expenses can only be changed by Congress, so it is no surprise that rate remains the same as 2013 at 14 cents per mile.)
Why do you care? These are the rates used in deducting costs for using a vehicle for business, medical, moving, or charitable purposes. Most commonly, this is the rate used by employers to reimburse employees for use of their personal vehicles for business purposes (the employer then takes a corresponding deduction for the amount reimbursed). Employers are not required to reimburse employees for such costs, and even if they do so, employers are not required to use this rate. If an employee does not get reimbursed, the employee can deduct the cost at the standard mileage rate. In that situation, the employer does not get a deduction since no reimbursement was made. (Alternatively you can keep track of and deduct the actual expenses, but using the standard rate is much simpler.)
Keep in mind the new rates are effective for miles driven starting January 1, 2014. Any expenses occurred in 2013 claimed on a return filed in 2014 (for tax year 2013) will still use the 2013 rates.