Box 4 ("Adjustments made for a prior year") shows any refunds during the current year for payments of "qualified tuition and related expenses" reported on a 1098-T for a prior tax year. For example, if you paid Winter 2009 registration fees when due in December 2008, "qualified tuition" for that quarter would have been reported on your 1098-T for 2008. If you subsequently received a refund of Winter 2009 registration fees in January 2009, the amount refunded would be reported in Box 4 for tax year 2009. Refunds may be the result of changing from full-time to part-time study, nonresident to resident classification, or cancellation/withdrawal.
If you access your record at Tab Service (TCS) student site, you may view and print copies of your 1098-T and "financial supplement." At the web site, the expense categories in Part 3 of the "financial supplement" are linked to more information. For example, just click on a link for "Regular Session Fees," and you will see the details (dates, descriptions, amounts) for all transactions that were compiled into that category, such as:
The amount in Box 4 may reduce any allowable education credit you claimed for a prior year. For more information, refer to "When Must the Credit be Repaid (Recaptured)" for the Hope and Lifetime Learning credits in Publication 970: Tax Benefits for Education [download].