The American Taxpayer Relief Act of 2012 restored parity between the monthly limit for mass transit and qualified parking, retroactive to 2012. How can an individual retroactively take advantage of this change in filing his/her 2012 federal income tax return? Is it based on the actual amount paid for transit up to the limit and can the individual claim a tax credit for the difference. Assume an employee participated in his/her employer's qualified transportation fringe benefit program during 2012, electing a mass transit pre-tax amount of $125 and that his/her mass transit fare exceeds even the $240 adjusted limit. If the monthly fare were equal to $250 and the individual elected $125 in pre-tax amounts and $125 in after-tax payroll deductions, could the individual claim a tax credit equal to the FICA and federal income tax withheld on the additional monthly $115 s/he is now able to claim retroactively?